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magazine 

for radio amateurs 



SI. 00 
January 1973 

26009 



















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INC. 




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MAXIMIZE 
YOUR AMATEUR RADIO 



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BUILT-IN 1 



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TOP BAND SYSTEMS, INC 



1839 Redondo Ave., Dept. 8B, Long Beach, Calif. 90804 USA 




magazine 

for radio amateurs 



#148 JANUARY 1973 



FEATURES 

4 Never Say Oie W2NSD/1 

5 SSTV Scene 
10 AIMS AT News 
12 Repeater Update 
12 50 MHz Sand 
12 With the FCC 

14 The Travelling Ham 

15 MARS 

16 Hamburgfar 

17 DX Footnotes 

19 Social Events & Contests 

20 New Products 

21 Amateur Radio and the I.T.U. 

24 Sneaky FCC Proposal 

139 Letters 

144 Caveat Emptor 

160 Propagation 



EDITORIAL STAFF 

Wayne Green W2NSD 
Keith Lamonica W7DXX 
Ron Subka WA9FPP 
Yvette Grimes WA8ULU 

ASSOCIATES 

Jim Kyle K5JKX 
Mike Frye WB8LBP 
Bill Turner WA0ABI 
Jim Weir WB6BH1 
Harry Simpson A4SCF 
Dave Ingram K4TWJ 
Bill Hoisington K1CLL 

PRODUCTION AND ADVERTISING 

Philip Price 
Lynn Panciera-Fraser 
Ruthmary Davis 
Bill Sundberg 
Janet QxJey 
Bill Suderman 
Karen Hebert 
Cynthia Schlosser 
Biff Mahoney 

BUSINESS 

Gigi Sage 

CIRCULATION 

Dorothy Gibson 
Barbara Block 
Ace Goodwin W1GRO 
Ginger Pettee 

TRANSPORTATION 

Mark Kearney 

PROPAGATION 

John Nelson 

DRAFTING 

R. K. Wildman W6MQG 
Bill Morelio 
Wayne Peeler K4MVW 
T. M. Graham WSFKW 



29 Obscene Commission Petition , . . W2NSD 

That hints of sedition and of coition. 
31 Minds Will Boggle When You Add w , . W10DI 

This Handy -Ta Iky Touch tone Pad 
33 A Widespaced Beam > , . VE3CFK 

Is the DXers dream. 
37 To Visit Yaesu, You Should Plan . WB61ZF/YB8AAP 

When next you travel to Japan. 
39 Chances Are That You're Boun'ter . . KL7GGB/4 

Love this JC KC counter. 
47 Speech Processing Gives More Power W0YBF 

To transmit nonsense by the hour, 
53 Try This Tricky Two Tone Test Set W6GXN 

It's not the worst, it's not the best set. 
60 The Sunspot CycleFrom 1750 . VE3CEA 

Tells us when DX is going to be nifty. 
65 An FM Tester and Frequency Meter . . VE7ABK 

Will put you right into your local repeater. 
71 New DX Award Announced . . . . . K9AZG 

For ops who try, but then get trounced. 
73 A Tilt-over Tower, Simple and Neat - W2ANT 

For chickens who panic above 20*. 
77 The New J-License Apparently Can WB5EBC 

G»ve ham supremacy to Japan, 
79 A Simple Kit for $18 . . K1CLL 

Makes a converter for 6m scholars- 
o*s ne nam l>ontent s ,«.*»*.■ + ,*,*,,. ».*!»,■.. •.»*•« **»!»* + * Lamomca 

The wife's laments, 
85 Kick Heterodynes in the Crotch .............. G8ABR 

With a tunable filter notch. 
89 One KW P.E.P . WA9JMY 

To help you make DXCC. 
97 High Power Silicon, Theory and Practice WB4LVA 

Proving that Beta can often be fractious. 
99 An LC. Ten Meter Tuner .......... ■ , . K1CLL 

Build it not later, but sooner. 
1 10 A Sturdier Quad in Unusual Form . . . WB2HYW 

To defy the wind and even a storm. 

1 12 Two Small Changes You Can Make . . . . , VE6TW 

To slightly improve your 4A Drake. 

1 13 Behold a Dandy Noise Defier . . EI4R 

Double diode rectifier. 
115 An Improved AGC Conception ZL2BDB 

For better CW and SB reception. 
1 21 Let Your Transformer Toil . WA0ABI 

In a bucket of oil. 
126 Having More Fun W3GHZ/0 

With the HAL ID- 1 
130 Build a Slow Scan Picture Taker . . , • . , , K4PRT 

From a Pofaroid 230 Copy Maker 
133 Build the Ferrous Wheel CW Key K6QKL 

And pump your way to satori. 



73 Magazine is published monthly by 73, Inc., Peterborough, New 
Hampshire 03458. Subscription rates are $6 for one year in North 
America and U.S. Zip Code areas overseas. $7 per year elsewhere. 
Two years $11 and $12 overseas. Three years, $15, and $16 
overseas. Second class postage paid at Peterborough NH 03458 and 
at additional mailing offices. Printed at Menasha, Wisconsin 54952 
U.S.A. Entire contents copyright 1972 by 73 Inc. t Peterborough 
NH 03458, Phone; 603-924-3873. 



JANUARY 1973 



■ 



— 




EDITORIAL BY WAYNE GREEN 



REPEATER GROUP ACTIVITIES 

One of the great benefits of repeat^ 
ers Is being passed up - mo re's the 
pity. Every member of a repeater 
group has one thing in common — the 
ability to communicate through the 
repeater, For some strange reason this 
unique ability is not being taken 
advantage of. 

There are several valuable functions 
that can be carried out via the repeat- 
er — functions which might help to 
build the club in members — in pres- 
tige — and in service, Obviously the 
repeater can be used to carry an 
nouncernents of interest to the 
group — meeting announcements — 
repeats of ARRL bulletins- FCC re- 
leases — propagation news — and even 
DX news, if there is some value in this 
to some ops — news of nearby repeat- 
er group meetings and functions — 
hamfest and convention news for the 
near and far future — plans for outings 
such as Field Day, VHF Contests, 
stuff like that - and plenty eta If 
every member of the club was vying 
to bring news to the repeater, it could 
be interesting and valuable. 

Suppose the news time is set at a 
convenient time every night, perhaps 
8 PIVL The club trustee can officiate 
and solicit news items from members. 
It could be a lot of fun and help to 
bring the club together — plus increase 
interest in club functions. 

The next step is to set up weekly 
technical symposiums — with one 
member on tap to give a talk and then 
answer questions from all the listen- 
ers. This can be taken from the 
License Study Guide series in 73 and 
will help members prepare for their 
higher licenses. 

How about code practice? Why 
not? A fifteen minute code practice 
session every night would soon have 
every club member ready for that 
General license. You could even go on 
to Extra, if there is interest. You can 
use code records, tapes or a member 
with a key — if there is one. How 
about starting those code sessions at 
7:45 and then give a five minute break 
at 8 for identifying — then on to the 
bulletins and stuff? 

There is little doubt that you can 
build up quite a listening audience to 
such goings on. You will find that not 



only are all of your members making a 
big effort to tune in, whether they are 
at home or in the car, but you'll also 
start getting listeners with scanner 
receivers. 

GETTING RICH 

The more I think of it, the more 
I'm convinced that one of the really 
great opportunities open to radio ama- 
teurs is in the selling and installation 
of security devices. 

Our radio and electronic back- 
ground gives us what we need in the 
way of skills for designing and install- 
ing systems. 

It is a business that can be started 
in your spare time and requires no big 
investment in equipment or offices* 
You can get started with little more 
than some letterhead and a phone 
number. 

The market is virtually unlimit- 
ed — every home, office, business, 
warehouse, etc., is a prospective cus- 
tomer. You can get started with small 
home installation and work your way 
up to large plants and even entire 
towns. 

Your sources of equipment are 
simple to locate — several distributors 
have excellent catalogs out You can 
sell the system — take a deposit for 
the job - order the equipment with 
the deposit - and then make your 
profit when the job is done and 
working. And then there are the re- 
siduals - the service contract which 
brings in money from then on. 

If you have any question about the 
validity of the idea, just ask your wife 
whether she would like to have an 
alarm system or not. When you are 
away she will feel a whole lot safer if 
there is an alarm. You are fortunate if 
you haven't been burglarized as 
yet — and the chances are that you 
have at least one neighbor who has 
come home to a big surprise — like no 
more television set— no hi-fi — no 
cameras — the works, 

Once you get started m your spare 
time the business will take over and 
you'll soon be working full time — 
and then some. Then comes em- 
ployees — salesmen — bookkeeper — 
and branch offices. 



If you do get into this business you 
would do a lot of fellow amateurs a 
big favor if you would write to 73 and 
tell us how 'you are doing. If you 
manage to discover some pitfalls you 
could pass along the word so we could 
be sure that no one else misses them. 

Do write. 

AM DEAD YET? 

The FCC warning about using AM 
on the 20-40-80 meter bands was 
strongly put in Docket 19162 which is 
effective November 22nd. Paragraph 7 
states that "... we strongly urge 
that . . . full power double sideband 
(AM) emission not be used in the 
lower four HF bands except in an 
emergency , . . J The message is clear. 

Wondering how this edict would be 
received by some of the AMers on 
20m, I tuned up the band the other 
evening and heard W6GS in contact 
with a W0 and he was bragging that he 
was one of a substantial group of 
AMers, mostly running kilowatts, who 
were holding forth on the band. When 
he finished his contact I broke in to 
ask what effect the new regulations 
requesting that AM not be used were 
going to have. I got my answer short 
and sweet when he called me a liar 
three times and then switched his rig 
off. 

While I was disappointed to hear 
this CB-type operation from an old 
timer with a two letter call, I can 1 ! say 
that I was honestly surprised, for I 
realize that the emotional reaction to 
being asked to quit AM is just as 
strong as was the reaction when the 
FCC said no more spark in the 20's. 

How much nicer for all of us are 
the chaps who embrace new ideas and 
new modes - the fellows who get into 
slow scan - satellite relaying - like 
that. We wilt always, have a few 
curmudgeons who will fight progress 
to the last ditch r rationalizing as they 
go down. The FCC is, for once, stating 
the majority opinion when they say 
that we really can't afford the luxury 
of AM on the lower bands, 

FIELD DAY PLANNING 

The Foothill Amateur Radio So- 
ciety (Mt View, CaU brought up a 
very interesting point for Field Day 
committees to ponder when they are 
making their plans for 1973. 

Ted Harris W8RPA/6 did some re- 
search on the average number of 
contacts scored by the five top clubs 
in each transmitter group over the last 
five years and put the info on a chart, 
The result is fascinating and seems to 
defy logic. At the very least there 
seems to be a lot to learn from it. 

Plotted on the chart you can see 
that the number of contacts made per 
transmitter drops off after two trans 



73 MAGAZINE 



mitters. Three transmitters did not 
result in any more contacts than two! 
And four didn't help matters very 
much either. Nor did the fifth. The 
sixth transmitter seemed to make 
more of a difference — perhaps that 
one should have been used in third 
place. The seventh transmitter must 
have broken down so often that nunrv 
ber six had to take time off to help fix 
it. And how about the nine transmit- 
ter clubs doing worse than the two 
transmitter efforts! How is it possible 
to make fewer contacts with nine rigs 
than two? Perhaps they were all on 
the same band. 






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1600 

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1200 

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XMTRS 

It would appear that a whole lot of 
planning is needed to change this 
weird pattern. There must be some 
way to make more contacts with three 
stations than two! 

Continued on page 142 




Dave Ingram K4 TWJ 

Rte. 1 h Box 499, Eastwood Vil, SON 

Birmingham A L 352 10 



Last year during the worldwide 
Slow Scan contest there was an ap- 
parent trend toward white lettering on 
a black background. If I were to make 
an educated guess on this year's trend, 
I would probably say 4 second i.d. 
frames will be quite popular. 

A 4 second frame displays your 
call, for example, on the top half of 
the screen, then as the trace nears the 
middle of the screen, a 1200 Hz 
vertical "blip" comes along and resets 
it to the top, and the procedure is 
repeated. Since your call is now being 
presented twice as often on the top 
half of the screen, while the bottom 
half is not being swept, the result is a 
brighter image, and if QRM "zaps" 
part of your call on the first sweep, 
chances are the second sweep will fill 
in the gaps, thus stiff making your call 
perceptible. How do you obtain 4 
second frames from your gear? Well, 
the vertical rate control may adjust 



down to a 4 second rate, or IC 
"counters" can be tapped at this 
point. If you don't care to go into 
your commercial gear, just make up 
some 4 second tape loops (I described 
tape loops in the September '72 
column). 




First SSTV QSO via Oscar 6. Not bad! 

Don Miller W9NTP and Phil 
Howlett WA9UHV have laid claim to 
the first SSTV QSO via an amateur 
radio satellite. During orbits 30 and 
41 they successfully exchanged rea- 
sonably fair pictures through the then 
4-day-old Oscar 6. Although they had 
managed to exchange approximately 
40 partial frames during earlier orbits, 
it was not until October 19 that 
pictures approached 'solid copy' 
state. This month's "Oscar 6" picture 
(compliments of W9IMTP) was one of 
the first few received by Don from 
WA9UHV. Not bad, eh? Probably you 
noticed the two or three Slow Scan 
signals through the satellite during 
each pass varying tremendously in 
level. This was due to the CW signals 
'loading down" the little "one watt 
repeater/ 1 Here in Alabama, the only 
distinguishable pictures (during that 
first week of Oscar 6) were from 
WA9UHV, as he and W9NTP tried for 
a perfect exchange. Now, since the 
satellite has been up a while, activity 
has probably settled down to where 
Slow Scan is easier through the satel- 
lite., , look in some night between 
29.450 kHz and 29.550 kHz (W1AW 
nightJy bulletins give times of equa- 
torial crossings). I think you will 
agree, Slow Scanners have the persis- 
tence of a P7 tube, and the enthu- 
siasm of a firecracker. 

The (dependent sideband system 
(transmitting audio on either upper or 
lower sideband, and video on the 
other (simultaneously) is growing in 
interest, and may become quite popu- 
lar during '73. W7FEN, the "Father of 
the ISB idea/' and W0LMD/4, have 
developed ISB units for use with 
commercial gear, like the Heath Trans- 
ceivers. I understand W0LMD's unit 
uses a pair of surplus Collins filters, 
and has exceptional SB to SB and 
carrier suppression. If you're seriously 



interested in this system you might 
contact either Gervie W7FEN or 
Robert W0LMD for circuits and specs. 
If you haven't already heard, 
another company, Thomas Elec- 
tronics, Box 572, Hendersonville TN 
37075, has recently entered the Slow 
Scan field. The info on their gear 
looks great, Their momtor displays a 
4.5 in, picture, has an attractive alu- 
minum CRT bezel, sync tuning meter, 
and vertical retrigger button mounted 
on the front panel I think their 
camera is a real winner. Slow and Fast 
Scan outputs are provided on rear 
panel jacks. In fact you have a choice 
of video or rf Fast Scan output; thus 
you can use your regular TV set as a 
Fast Scan monitor (even while tele- 
vising Slow Scanf), Further, the Fast 
Scan output is adjustable from Chan- 
nel 2 through 6, so you can pick a 
blank channel for your area. Another 
big advantage of this camera rs the 
built in ac power supply; thus the 
camera is completely self contained 
(you SSTVers with only a monitor 
and tape recorder take note here). I 
suspect we wilt hear quite a bit more 
out of this company during 1973, 

THE MXV-100 MONITOR 




One of the newer companies to 
enter the SSTV field is J & R Elec- 
tronics of Poughkeepsie, New York, 
who is manufacturing the MXV-10G, a 
superb slow scan monitor. 

The monitor is built in a Heathkit 
styled cabinet the same size and color 
of the SB-20Q. The front panel is dark 
green plexiglass with lettering behind 
the plexiglass, resulting in quite an 
attractive unit that matches Heath 
equipment perfectly. 

Inside, viewed from the front, the 
cathode ray tube is mounted on the 
left and the two plug-in printed circuit 
cards are mounted on the right. The 
smaller card is the high voltage power 
supply and the larger card contains 
the major monitor circuitry. A third 
printed circuit board is mounted ver- 
tically in approximately the cabinet's 
middle. This contains the interconnec- 
tions for the other two boards, and 
some of the low voltage power supply 
components. The remaining low vol- 
tage power supply components are 
mounted under the chassis. A 6FG6 
tuning eye tube is mounted on the 
front panel for aid in tuning signals 



JANUARY 1973 




Henry Radio proudly announces the new Tempo line of amateur 
FM transceivers for the 146 and 220 MHz bands. The Commercial 

Line transceivers are so fine they can meet the tough FCC 

requirements for Type Acceptance in commercial two-way service. 

A broad fine of transceivers so modestly priced that any amateur 

can own one. Transceivers that defy comparison for both 

performance and value. Transceivers that are not a dream for 

tomorrow but are available right now . . . today 



TEMPO'S "COMMERCIAL LINE" TRANSCEIVERS... THE BEST! 









TEMPO CL 220 



*tf 



TEMPO 



i 



.BMUHMEm UN I 



* # t l# *•«*'*■* '• J 



As new as tomorrow! The Tempo Com- 
mercial Line VHF transceivers offer com- 
mercial performance at amateur prices, 
Both units include an audio limiter to as- 
sure constant deviation at all times and 
an instantaneous impulse squelch. Micro- 
phone, power cord, mounting bracket 
and one pair of crystals is included. 

GENERAL SPECIFICATIONS: 

• Frequency Range: 220-225 MHz 
(2 MHz operating range) 

• Number of Channels: 12 channel 
capability for transmit and receive 

• Microphone: Dynamic with coil cord 

• Dimension: 2.36" H x 5.90" W x 7.66" D 
m Weight: 4,5 pounds 

• Frequency Stability: ±0.001% 
(-20° to +60°) 



• RF Power Output: 10 Watts or 3 Watts. 

• Output Impedance: 50 ohms unbalanced. 

• Sensitivity: 0.5 microvolts nominal for 

20 db quieting. 

• Spurious & Image Attenuation: 70 db 
below desired signal threshold sensitivity. 

• Adjacent Channel Selectivity {15 KHz 
channels): 70 db attenuation of adjacent 
channels, 

• Type of Receiver: Dual conversion 
superheterodyne. 

• Audio Output: 2 Watts minimum 

w/ internal speaker (at less than 10% 
distortion) 

• The price: $329.00 

TEMPO I CL 146 

• Frequency Range: 146-148 MHz 

• Same general specifications as CL 220 

• The price: $279.00 



THE TEMPO "VALUE LINE"... THERE'S NO BETTER BUY! 



i£3 



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'ftttllitff* 



TEMPO Imp 



Truly mobile, the Tempo/ fmp 3 watt por- 
table gives amateurs 3 watts, or a battery 
saving Vz watt, FM talk power anyplace at 
anytime. With a leather carrying case in- 
cluded, this little transceiver will operate in 
the field, in a car, or at home with an acces- 
sory AC power supply* The battery pack is 
included. Frequency Range: 146-148 MHz 
The price: $225.00 

{Accessory rechargeable battery available: 
S22.I 




TEMPOimh 

So much for so little! 2 
watt VHF/FM hand held. 
6 Channel capability, 
solid state. 12 VDC, 144- 
148 MHz (any two MHz), 
includes 1 pair of crys- 
tals, built-in charging 
terminals for ni-cad 
cells, S-meter, battery 
level meter, telescoping 
whip antenna, internal 
speaker & microphone, 
$189.00 




TEtfP&Imri 



no im 



v\ 



Jk 



IVl'l I 



TEMPO fmv 2 



So much for so little! This little 10 Watt VHF FM 
transceiver offers high quality performance and 
features usually found only on more expensive 
units. Features such as AFC on receive and sepa- 
rate switchable Transmit/Receive sections. In- 
cludes mounting bracket, heavy duty power cord 
and provisions for accessory AC power supply. 
Frequency: 146-148 MHz, 11 channels, 25 KHz 
channel spacing, 13.8 VDC ±10% operation 
(standby -100 ma, receive —150 ma, transmit 
-3.0 amp.) 
The price: $199.00 



TEMPO ITPL 

high power 
Im amplifiers 



Miniature power houses! Operates directly from a 
12 VDC power source, automatic antenna switch- 
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state of the art design practices, making it vir- 
tually immune to damage due to high VSWR or 
misloadfng conditions. 



MODEL 


POWER 


POWER 


BAND 


PRICE 


NUMBER 


INPUT 


OUTPUT <min) 






TPL1002-3 


5 to 25W 


100-135W 


2M 


3220,00 


TPL1 002-3 B 


1-3W 


sow 


2M 


$235.00 


TPL802 


5W 


SOW 


2M 


$180,00 


TPL802B 


1 to 3W 


80W 


2M 


SI 95.00 


TPL502 


5 to 1 5W 


35-55W 


2M 


$105.00 


TPL502B 


1 to 3W 


45W 


2M 


$130.00 


TPL252-A2 


1W 


25W 


2M 


$ 85.00 


TPL445-10 


1 to 2.5W 


12W 


440MHz 


$125 00 


TPL445-3G 


4W 


30W 


440MHz 


$215 00 


TPL445 30B 


tw 


30W 


440MHz 


$235,00 


TCP 12A Control Head - . - 


$32.00 







11240 W Olympic Blvd r Los Angeles, Calif 90064 213/477 6701 

< 931 N Eyelid, Anahe ti. Calif 92801 714/772 9200 

Butler, Missouri 64730 816/679 3127 

Worttf'.f Largvaf Distributor of Amtih'ur Undto Equipment" 



I 



AVAILABLE AT SELECT DEALERS THROUGHOUT THE U.if. 




Jmide vww of ihe MXV- J 00 monitcr 

properly. Except for the 6FG6 and 
cathode ray tube, the monitor fs all 
solid state. 

During actual operation, an incom- 
ing slow scan signal is fed to the main 
monitor circuit board, and is then 
limited and amplified. The 1500 to 
2300 Hz tones are then passed 
through the low pass filter to the 
video amplifier. Output of the video 
amplifier (approximately 100V) is suf- 
ficient to totally cut the beam off on 
absolute blacks, even when the bright- 
ness is extremely high. The sync 
pulses are taken directly from the 
limiter, and processed through two 
filters, the noise immunity circuits, 
and the pulse shapers, before reaching 
the sweep circuits. The result is a 
monitor that really "digs in" to get 
those slow scan pictures. We particu- 
larly liked the sync circuitry of the 
MXV 100. Briefly, it works like this; 
A 30ms 1200 Hz pulse is received and 
a picture starts. The input gate then 
closes and doesn't open again until 
time for the next pulse; approxi- 
mately 7% seconds for the vertical, 
and 50ms (length of each line) for the 
horizontal. If a pulse is received, the 
trace is reset and the process is re- 
peated. If no pulse is received, the dot 
stays deflected off the screen. This 
type of gated input makes false trig- 
gering of either the vertical or hori- 
zontal practically impossible. A 
manual vertical retrace button is 
mounted on the front panel in case a 
retrace pulse is lost. 

The noise immunity circuits in the 
MXV- 100 compare the input pulses 
against a predetermined level. If they 
are of the proper amplitude, they are 
accepted as sync pulses. If they are 
too low, they are rejected as noise. 
The circuit will follow a signal right 
down to the "trash" level before 
rejecting it. Remember, the active 
filters have already ascertained the 
pulses are 1200 Hz pulses, 

The unit we received for evaluation 
did a beautiful job. During some tests, 
using taped pictures with known con- 
tent, other local slow scanners and 
myself noticed small details we pre- 
viously had not noticed significantly 
with our own monitors. The pictures 
appeared exceptionally clear and quite 
bright. I think this is mainly due to 
the aluminized 5AHP7, an electromag- 



neticaJly deflected and electrostati 
calfy focused cathode ray tube, with 
5500V on the accelerator. Also, there 
is no yellow filter on the face. Al- 
though one can easily be added, we 
personally prefer the unfiltered 
screen. I found a viewing hood un- 
necessary. In fact, I didn't even cover 
the window during afternoon opera* 
tion, when the sun reflects into the 
shack (this usually requires a hood 
with my 5UP7 homebrew monitor), 

The low pass and noise immunity 
circuits did a superb job pulling signals 
right out of the mud. Often I could 
read a station's call sign off the screen 
before I could hear them give their 
call. If QRM came on close to T200 
Hz {and it had to be close - the filter 
is pretty sharp) for, say, one second, 
the monitor would merely leave a 
blank space of 15 lines [120 lines 
divided by 8 seconds =15 lines per 
second), then immediately lock back 
and resume the picture. In fact, the 
ability of the monitor to "latch onto" 
a signal instantly was quite attractive. 

Although the 5 inch screen may 
seem slightly small to some of you 
(there is a trend toward the 7- inch 
screens), this was fine for me. Possibly 
this is because I located the MXV 100 
right above my present 5 inch moni 
tor, which was placed for perfect eye 
to screen distance previously. 

The sync tuning eye is a unique 
feature of the MXV 100. Since the 
sync frequency filters are sharply 
tuned, when a signal is off frequency, 
the screen is dark, instead of streaked 
to one side or the other and the eye 
tube (like on some stereo tuners) is 
"open." As the signal is tuned on 
frequency, the eye closes (again, like a 
stereo). This foolproof tuning has to 
be seen to be appreciated. 

The unit uses top quality parts 
throughout, and boards are G 10 class. 
All inline integrated circuits are 
plugged into sockets for easy ser 
vicing. 

I noticed the deflection yoke was a 
Stancor item, with a long part num- 
ber, evidently specially made for J & 

All connections to and from the 

monitor are on the rear of the unit, 
and connection to your rig is des- 
cribed fully *n the onerating manual. 




All in all, we found the MXV-100 a 
real gem of a monitor. 

I understand J & R is working on a 
slow scan camera system, which may 
be offered soon in an attractively 
priced monitor camera package. 

Once again, the manufacturer is J & 
R Electron tcs r Box 7646, Poughkeep- 
sieNY 12601. 

. . .K4TWJ 



ENGLISH 





Are you interested in seeing what 
wireless was really like in the twenties, 
and hearing those crystal-sets and 
horn speakers swarkingaway . . . well, 
just pop over to England where 
they've opened a Wireless Museum, 
the only one in the world where the 
visitors are permitted to handle the 
exhibits! There are dozens of sets on 
view, many of them dating from the 
early days of broadcasting in 
England - 2LO opened up in Novem- 
ber 1922. There is even one which was 
used in the trenches during World War 
I. The Museum is run by the recently 
formed Wireiess Preservation Society, 
devoted exclusively to the collection 
and renovation of wireless and elec- 
tronic equipment for purely cultural, 
educational and historical purposes. It 
is an entirely non-profit making or 
ganization, and all its officers are 
honarary. The hon/secretary and 
Musuem Curator is Douglas Byrne, 
G3KPO, of Homa House, Quadring 
Watergate, Spalding, Lincolnshire, and 
it would be advisable to contact him 
by ringing STD 077-584-485 prior to 
a visit to the museum. 



Close-up of the neatly engineered circuit 
boards. 



RRTY GEAR 



The Santa Fe Railroad has recently 
been replacing its in-service Model 14 
& 15 Teletype gear with more up-to- 
date units. It seems they had no idea 
that someone might still be interested 
in such 'out of date' equipment, so 
they sold most of what they had in 
ton-lots as SCRAP METAL ! Bill 
Johnston WB5CBC heard about this 
sacrilegious action and managed to 
have a hold put on the 120 or so units 
left. The gear is being sold as-is, but 
most were pulled right out of service 
and are in perfect shape. The units are 
along the Santa Fe's main line be- 



8 



73 MAGAZINE 



SQUELCH 



OFF , , , kiPUl 




escape from the 2 meter crowd 



The all new 



220 MHz 




FM-21 Transceiver 



puts you in tomorrow's channels today! 






220 MHz FM is the early solution to 
overcrowded 2 meter channels. Here's 
your chance to get in on the ground 
floor of the FM future. The new FM-21 
all solid-state transceiver is an oppor- 
tunity to "do it right" this time and 
start with the leader The FM-21 uses 
only 1 crystal in any channel ...one 
crystal gives you a separate transmit 
and receive frequency as well as auto- 
matic 1.6 MHz programming in the re- 
peat mode. We call this unique triple- 
duty crystal feature Clegg Crystal Saver 
Frequency Control. For the complete 
story, see your Clegg Dealer or call or 
write us today for detailed data sheet 
and avoid the crowd. 



CHECK THESE FEATURES 

8-10 watts output (minimum). 

Speech clipping. 

Sensitive receiver — .25 mv (max.) 
for 12 db Sinad. 

Selectivity — Adjacent channel (40 
KHz) down 50 db. 

Each crystal does triple-duty, pro- 
viding a transmit and receive fre- 
quency (Crystal Saver Frequency 
Control). 

Monolithic crystal filter. 

Compact, rugged, attractive. 



Amateur Net $299.95 



s* 



r.«H htt0 ™*tm 



Gi 




. WmHMQHAL 




f 0i*jjl§!t3* 



£kBL 



DIVISION 



3050 Hempland Road, Lancaster. Pennsylvania 17601 

Tel: (717) 299-3071 Telex: 84-8436 



— 



tween Topeka, Kansas and Los 
Angeles CA, and must be picked up at 
their location. Prices range from $10 
for a Model 14 NonTyping Reperfera- 
tor to S25 for a Mode! 15 Page 
Printer, Contact Mr, C. (X Glover, 
Purchasing and Materials Dept, 
AT&SF RRY r P.O. Box 1674, Topeka 
KS 66601. 



AMSAT 




NEWS 



Mike Fry* WB8LBP 
640 Dauville Dr. 
Dayton OH 45429 



THE OSCAR 6 AMATEUR 
SATELLITE IS IN ORBIT! 







NASA team inspect or swabbing down AOC 
(courtesy NASA-USA F). 

OSCAR 6 was launched from 
NASA Western Test Range on Sun- 
day, October 15 r 1972, piggyback 
with the NOAA 2 weather satellite. Its 
big Thor-Delta rocket put it into orbit 
over the South Pole. It flew across the 
Equator east of Africa, and the space- 
craft was ejected over the Mediter- 
ranean, OSCAR came to life irrv 
mediately, and European and African 
amateurs reported hearing signals 
through the satellite repeater. 

OSCAR is in a circular polar orbit 
910 miles high. Thus it is Irne-of-sight 
to stations nearly 2,500 miles away. 
Amateurs 5,000 miles apart should be 
able to communicate through it 
OSCAR circles the earth every 115.0 
minutes at an inclination of 101.77 
degrees. In that time the earth has 
turned to the east under it 28.75 
degrees in longitude, Therefore, if you 
have one official prediction, then by 
simple addition you can figure out all 
future equator crossing times and the 
corresponding longitudes, Copy the 
broadcasts from W1AW any night get 




Satellite as it is being placed inside 1TOS-D 
rocket (courtesy NASA-USAF). 

orbital predictions for the next day. 
The speed of the satellite is in excess 
of 15,000 mph, Hence the Doppler 
shift will make the signals slowly drop 
in frequency on your receiver as much 
as ±4Vz kHz each passage. The power 
output on ten meters is about a watt 
maximum to a dipole. 

OSCAR's repeater is entered on 
two meters - 145.90 to 146.00 MHz. 
Signals are relayed out on ten 
meters -29.45 to 29.55 MHz. You 
should hear signals throughout this 
100 kHz passband, and up to 50 kHz 
below and above it. All modes can be 
used through it r but CW and SSB are 
the most efficient Technicans are 
authorized to operate through the 
satellite by FCC waiver. The satellite 
is sun-synchronous, i.e., it will appear 
overhead at approximately the same 
times each day, around 9 AM and 11 
AM each morning, and 9 PM and 11 
PM each night, regardless of your 
location. The morning passes come 
down from over the North Pole, and 
the night passes come up from across 
the Equator. A flyover lasts only 
about 20 minutes, so you must know 
the times pretty closely, If you have a 
ten meter beam, lucky for you. Most 
of us are using just dipoles or long 
wires. Just 10 watts of two meter 




power is adequate to work through 
the satellite, particularly on an over 
head pass. 

K2RTH of New York was able to 
hear his own signals through the satel- 
lite when it was over Dakar in W, 
Africa, over 3,000 miles away. Ama- 
teurs in over two dozen countries are 
being heard and worked through 
OSCAR. OSCAR also carries a beacon 
on 435.10 MHz. It has 300 mw 
output and sends 24 three-digit num- 
bers representing telemetry in Morse 
code at 10 or 20 wpm. This tells us 
the operating conditions within the 
satellite. 




OSCAR 6 hunch, Oct J 5, 1972 at 1719 
GMT (courtesy NASA-USAF). 

OSCAR 6 has solar cells and a 
nickel-cadmium battery and was built 
for a year or more of useful life. So 
there is plenty of time for you to get 
equipped on 145 and 435 MHz. 

Keep a log of stations heard and 
worked, with date and time. Submit 
your log periodically to AMSAT and 
you will receive a colorful QSL in 
return. 




AMSAT OSCAt 

*■»!■■* Saiallit* Carper**! 




Satellite and launch vehicle on the pad just 
before countdown started (courtesy 
NASA-USAF), 



OSCAR 6 QSL card- To receive one* please 
send report to AMSAT, Telemetry Dept, 
PO. Box 27, Washington, D.C. 20044. 

For more information or problems 
you may be having, please send SASE 
to me and I will do my best to help 
you. 

i would like to thank Palmer E. A. 
Back WB6QLY for helping me get the 
photographs. 

WB8LBP 



10 



73 MAGAZINE 





Get total 146-148 MHz coverage 
without buying a crystal! 



The modified Clegg FM 27B transceiver 
now covers the entire range of 146-148 
MHz . , . and needs NO additional crys- 
tals. It's the only 2 meter rig available 
now with built-in total coverage that 
also offers greater than 25 watts output 
power, uses 10 !C devices, and has 
Teflon* wiring throughout Not a single 
bi-polar device is in the RF path in 
transmitter or receiver . ■ - ensuring 
greater reliability. Accessory power 
supply and sub-audible tone on transmit 
are available too. At home or in your 
car, the FM 27B gives you the ultimate 
in total 2 meter performance. See your 
Clegg Dealer NOW or write or phone 
us today for detailed data sheet on our 
2 meter leader. 

Amateur Net $479.95 J$zf^${ 
WERHAWm 



CHECK THESE SPECIFICATIONS 

GENERAL 
POWER REQUIREMENTS: 12 to 14 VDC 

Current Consumption at 13.5 VDC: 

Receive: 4 amps squelched, L2 amps unsquelched. 

Transmit: 6 amps max. 
DIMENSIONS; 1W x 3V4* x Wa * deep; 4 lbs, net 

weight, RECEIVER 

TUNING RANGE; 146.00 to 148.00 MHz, continu- 
ously tuneable with reset capability of approx. 

I KHz to any frequency in range. 
SENSITIVITY : .35 ^v max. for 20 db quieting; .1 jiv 

for reliable squelch action. 
SELECTIVITY: 11 KHz at 3 db; Less than 30 KHz at 

70 db. Adjacent (30 KHz spaced) channel rejection 

more than 70 db. 
AUDIO OUTPUT: 2.0 watts (min,) at less than 10% 

THD into internal or external ohm speaker. 

TRANSMITTER 
TUNING RANGE AND CONTROLS: Same as 

RECEIVER. 
POWER OUTPUT: 25 watts Min, into 50 ohm load, 

PA transistor protected for infinite VSWR. 
MODULATION: Internally adjustable up to 10 KHz 

deviation and up to 12 db peak clipping. 




£te#L 



*QuPont trademark 



DIVISION 



^tPOllliO* 



3050 Hempland Road, Lancaster, Pennsylvania 17601 
TeL (717) 299-3671 Telex: 84-8438 




^REPEATER UPDATE 

LISTENING 

94 76 88 73 70 64 82. . 




AR 


WB6KFK 


Forest City 


16-76 


CA 


WA6T0D 


LA. FM 147.435-146.40 
AM 147.405-145.40 


CT 


W1WHZ 


Norwalk 


147.99-39 


MA 


W1DC 


Billerica 


147.72-12 


PA 


WA3KFX 


Hal lis 


01-61 


PA 


WA3KXI 


Lancaster 


34-94 


PA 


WA3CAG 


Trewose 


19-79 


Rl 


K10HE 


Delete 





RTTY REPEATER 

A new FM repeater serving the Bay 
Area RTTY stations has just been 

announced, according to Tom Nelson 
W6QGN. Using 2125 mark/2975 
space tones at 60 wpm, it has an input 
of 147.93 MHz and an output of 
147,33 MHz, 

The new repeater is a joint effort of 
WA6EUZ and WB61MP and will tem- 
porarily operate under the latter's call. 
It will be an open repeater and all 
amateurs are invited to participate. 
Although presently installed as a COR 
{carrier) access direct audio device, 
future modifications will provide sig- 
nal regeneration, automatic date/time 
entries, and other special features. 






Bill Turner WA0ABI 
Five Chestnut Court 
St Peters MO 63376 

A previous column made mention 
of WTWQ-TV with reference to this 
station being located in Indianapolis. 
W9JCU r who happens to be the Chief 
Engineer, sets me straight on the 
actual location, which is Terre Haute, 
Indiana. This is what happens when 
you don't make a log entry and rely 
on your memory for the details. 
Arden goes on to say that the GE 
Bat-Wing antenna on a 1000' tower, 
was loaded up on 6 during Field Day, 
and between the hours of 1:3 and 
6:00 in the morning, 22 States were 
worked. How would you like to have 
an antenna like that on a permanent 
basis 7 

WA1EXN reports conditions had 
been very poor until the opening of 
October 17th. Art says, 'This is the 
first time in 7 years of VHF opera- 
tions that signals ever pinned the S 
meter at slightly over 60/9. Ask 
WO HZ." Art worked WO's, W4's, and 



W9's during this one. A brief opening 
from Maine to Florida was noted on 
October 30th from 1436 to 1638Z, 
October 31st and November 1st 
brought very good aurora. I also 
worked these openings with very good 
results. Among those most active were 
K9HMB, K8BBN, WA8MLV (running 
a Yaesu transverter}, WA10UV, 
VE3FHK and WB3JCK. The most 
unusual contact reported was from 
the Chicago area to Casper, Wyoming, 

VE1ASJ is off the air on 6 at the 
moment due to a storm blowing a tree 
against his tower. A new tower is in 
the works and may well be in opera- 
tion by the time this appears in print 

W0TVD, Omaha, would be happy 
to sked anyone needing Nebraska. He 
runs a Swan 250C and a 6 element 
wide-space Telrex at 55 feet, Chuck 
says in his letter that W0CCD, known 
as "Grandma Lou", will be back on 
the air with a Swan and a 6 element 
Hygain thanks to her many friends 
around the country. I can personally 
verify that she made the grade. Just a 
few evenings ago I heard her talking to 
John WA0HTP. Chuck mentions the 
October 17th opening as having lasted 
around 5 hours, working its way down 
the east coast, across the Gulf states 
and finally ending up in the Texas/ 
New Mexico area. 

Bob WBBJHT, will soon has a new 
KW PEP linear on the air - in fact, it 
should be in operation by now. Bob 
will be running a pair of 
4x150A/7034's in a passive grid con- 
figuration similar to the one in the 
July 1969 issue of 73. 

Anyone interested in running a 
beacon will find any number of end- 
less loop tape recorders on the surplus 
market currently. These are usually 
described as 'message centers" or 
something similar. Prices run from S4 
to $12 depending on how deluxe a 
model you buy. The cheapest I have 
seen is from Burstein-Applebee, 
Kansas City, as S3.95. A few simple 
modifications are needed to make it 
acceptable for this purpose. I will be 
happy to send a list of hints to anyone 
interested, 

WA0ABI 



WITH 




FCC 



$jjpa* 



!$ 



m —. tl<-l*-1ft 





Keith Larnonica W7DKK/1, Managing Editor 
of 73, listening to the first "beeps" of 
Sputnik I a few years back (too many). 



OUCH! 
See the proposal on page 24! 

RM-1604 

Before the 

Federal Communications Commission 

In the Matter of 

Amendment of Parr 97 of the Ama- 
teur Radio Service Rules to revise the 
station identification requirements for 
transmissions of less than two mi- 
nutes. Order adopted October 20, 
1972. Released October 20 r 1972. 
By the Chief, Safety and Special 
Radio Services Bureau \ 

1, The Commission has under con- 
sideration a petition filed by Michael 
R. Beverly proposing amendment of 
Part 97 to change the station identifi- 
cation requirements for amateur radio 
communications of two minutes or 
less, 

2, The petitioner proposes to add a 
new subsection to §97.87 which 
would require the control operator of 
an amateur station to identify his 
station and the station being called at 
the beginning of a transmission and, if 
the transmission was less than two 
minutes in length, the concluding 
identification would consist of only 
the calling station's call sign. The 
Commission's Rules on station iden- 
tification require the control operator 
to identify both his station and the 
station he is calling at the beginning 
and conclusion of every transmission. 

3, The petitioner asserts that this 
proposed change will facilitate punc- 
tuality and efficiency for short ex- 
changes. Petitioner further asserts that 
compliance with our present identifi- 
cation rules is difficult with a very 
short transmission, 

4, The present station identification 
rule provides rapid identification of a 
station to prevent one way communi- 
cations broadcasting, identification of 
stations conducting international third 
party communications, and identifica- 
tion of stations conducting radio com- 
munications with stations in countries 
which ban communications with U.S. 
amateur stations. While the required 
form of identification may be some- 
what awkward during very short trans- 
mission, the reasons for this identifica- 
tion procedure remains the same re- 
gardless of the length of the communi- 
cation, 

5, The Commission, therefore, be- 
lieves that there is no justification for 
this proposed rule amendment. In 






12 



73 MAGAZINE 






REPEATER OWNERS 



Don't Take Chances. SENTRY offers custom made crystals made exactly 
to your specifications. When it comes to crystals for your repeater, BUY THE 
BEST -SENTRY. 



l i'vV-' i 



'.VjVi'i'i 



'.►.V-"-'-"''-'i 









REPEATER USERS 



If you want reliable access to the repeaters in your area, you want and 
need SENTRY CRYSTALS. SENTRY CRYSTALS are custom made for your 
rig. We don't stock a large quantity of crystals for a certain frequency and 
hope you can tweak them to frequency in your rig. We do offer FAST service 
on crystals made especially for you and your rig. If you want reliable, 
on-frequency operation, INSIST ON SENTRY. 




SENTRY MANUFACTURING COMPANY 

Crystal Park, Chickasha, Oklahoma 73018 



PHONE: (405) 224-6780 

TWX-910-8 30-6425 



JANUARY 1973 



13 



— 



view of the foregoing, the rule making 
petition plainly does not warrant 
Commission en banc consideration, 
Accordingly, the Comission by the 
Chief, Satety and Special Radio Ser- 
vices Bureau, pursuant to the autho- 
rity delegated in §0.332(m) of the 
Commission's Rules, ORDERS, that 
the petition filed by Michael R, 
Beverly is DENIED. 
Federal Communications Commission 

James E, Barr 

Chief, Safety and Special 

Radio Services Bureau 



990 kHz SPACING 

The proponents of discarding the 
adopted 600 kHz band plans ICARC, 
SERA, NERA, Texas, Central States, 
etc.) have listed a number of potential 
advantages of going to a wider input/ 
output spacing on two meters. It is 
instructive to examine the technical 
facts of the matter. 

The most frequently stated advan- 
tage of the wider split is a reduction in 
repeater receiver desensitization. Let 
us examine the actual numbers. Most 
FM receivers and transmitters have a 
selectivity characteristic which is 
dominated by two poles for strong 
off-channel signals greater than 200 
kHz (at two meters) removed from 
the desired frequency. The slope of 
such a selectivity characteristic is 12 
dB per octave. Therefore the reduc- 
tion in desensitization achieved by 
going from 600 kHz to 990 kHz 
separation is given by 

40 log io (990/600) = 8/7 dB. 
Since a typical duplexer has 90 dB of 
isolation, this improvement of less 
than 10% is hardly worth the effort 
and expense of a major recrystalling 
job. In addition, the power limitations 
imposed in Docket 18803 will make 
the wider split less attractive to those 
high power repeaters who used the 
additional few dB of isolation to 
compensate for marginal duplexer per- 
formance. (W1GAIM has shown that 
his duplexer design has isolation 
which is adequate for at least 60 watts 
of RF, which is 240 watts ERP when 
a 6 dB gain antenna is used. In fact, 
his duplexer is being successfully used 
with up to 200 watts of RF,) Even if 
the full 8,7 dB could be realized as 
improved receiver sensitivity, the in- 
crease in repeater range would be 
something less than a factor or two. 
Since a typical duplexer cavity has 30 
to 35 dB of isolation, we will not be 
able to use fewer cavities in a duplexer 
for 990 kHz spacing. 

It has been proposed that to ease 
the repeater user's burden, each exist- 



ing repeater should establish a second 
990 kHz repeater using the old output 
frequency for the input of the second 
repeater. Thus no one would be stuck 
with useless crystals. The fallacy here 
is that the new repeater's output and 
the old repeater's input are still sepa- 
rated by 600 kHz, and similarly for 
the old output and new input. There- 
fore, there is actually no gain in 
transmitter/receiver isolation if these 
two repeaters share one site. 

It has been claimed that the shift to 
990 kHz spacing will give us more 
repeater channels. Of course, this ad- 
vantage is negated by the proposal 
that every repeater group use two 
frequency pairs. At first sight, it 
would seem that 990 kHz spacing 
would yield 33 repeater channel pairs 
compared with 27 (an increase of 
22%). However, a guard band is re- 
quired between the repeater input and 
output bands to reduce mtermodu- 
tation interference to repeater inputs. 
There also is a demand for simplex 
channels on which no repeater 
operates. Thus the apparent gain in 
total number of repeater channels will 
not be realized in practice. 

The most common argument 
against, the existing 600 kHz band 
plan (half of the channels irvlow/out- 
high and half in-high/out-low) is that 
transmitters cannot operate efficiently 
over a 2 MHz spread in frequency. 
However, such arguments have no 
basis in fact. We have experimentally 
verified that the power output of the 
Motorola "SOD" transmitter is down 
only 1 dB ± 1 MHz from the frequency 

for which it is tuned up. This small 
reduction in output power will cause 
no perceptible reduction in communi- 
cation range. Therefore, if a transmit- 
ter is peaked at 146.94 MHz, it should 
conveniently covjer the entire FM 
repeater segment of 146-148 MHz. 

In general, receivers will not cover 
such a large frequency spread without 
a greater loss in performance, due to 
having a larger number of high-Q 
tuned circuits in their input stages, so 
that it makes good sense to keep all 
the output frequencies clustered to* 
gether. 

It has been claimed that it is im- 
possible to use a "sensitive solid state 
receiver" in a one-site repeater with 
600 kHz spacing. The experience of 
some of our more progressive repeater 
groups directly contradicts this. In 
fact, a properly designed solid-state 
receiver will be less susceptible to 
interference than will a more convex 
tional receiver using vacuum tubes. 
Modern solid state devices offer per- 
formance that could only be dreamed 
of a few years ago. 

Some amateurs feel that frequency 
synthesizer design will be more com- 
plex with the current 600 kHz band 



plan. However, those of us who have 
actually designed and built synthe- 
sizers know that no one offset is any 
harder than any other, provided it is 
an integer multiple of the channel 
spacing. From the user's point of 
view, it is easier to use an offset that is 
a multiple of 100 kHz, since the 
mental arithmetic is easier. 

Finally, we should go back a few 
short years in FM history and recall 
that our FM pioneers were satisfied in 
many cases with a 420 kHz split. 
Perhaps 90% of the repeaters in the 
U.S. are on the 600 kHz standard 
today. Let's keep it that way. 

L. D, Collins K4GGI 

S. J. Murray K1KEL 

P. Catala F2B0/W1 



* 



°0 9hm 



^°o 



'O 



oo 




Job Kasser G3ZCZ/W3 

1701 East West Highway* Apt. 20S 

Silver Spring MD 20910. 

Establishing communications with 
the locals when on a trip can be as 
difficult as you make it. If you can 
work into the area on the hf bands 
beforehand, you'll usually get a name 
and telephone number to call when 
you arrive. If you have a Technician 
call or do npt have any hf equipment, 
then get, a friend to call someone on 
the band for you. 

When you go take an up-to-date 

callbook with you. Take some gifts 
with you, too* If you are going over* 
seas don't forget to take advantage of 
the duty-free liquor and cigarettes 
available. They make very useful pre- 
sents. U.S. postage stamps and maga- 
zines or knickknacks are appreciated 
by those who collect the things. To 
another ham who homebrews, some 
of the more exotic (and expensive 
overseas) IC's or VHF power t ran sis* 
tors will be appreciated almost as 
much as gold ingots. If you did 
establish contact prior to your trip, 
you could always have asked what to 
bring. Twenty-one cent mint postage 
stamps will be appreciated by the 
DX'er who has to purchase IRC's to 
get QSL cards from stateside mana- 
gers. 

If you take a rig with you and get a 
permit, call in on a local frequency or 
repeater. Your foreign call or recipro- 
cal one and unusual accent will be 
recognized, and you will have a small 
pileup on your hands if you are on 
VHF, If you ask for information 



14 



73 MAGAZINE 



about clubs, stores and activities one 
or two telephone numbers are bound 
to be mentioned. 

If you don't take a rig, use the 
callbook blind, by looking up calls in 
the local area, then looking up the 
name and address in the phone book. 
This is not an instant success method 
because the chap may not speak 
English, or may not be at home or 
active, or may just be unfriendly. 

If you are able to monitor the local 
bands, then you can look up those 
calls that you hear in the call book 
and cross reference to the phone 
book. If you don't speak the local 
language fluently, then try to get 
someone else who can, to make the 
call — or if that is not possible, then 
practice the important sentences over 
and over again before making the 
call -ones like: "May I speak 

to " ( or, "I 

am from What ham 

activity is there in the area? 

Explain who you are, say that you 
are monitoring him but don't ever ask 
for an invitation to his home. Ask 
instead about local stores, clubs and 
activities in general. There is a 99% 
probability that he will invite you to 
his home, so why push yourself on 
him. Let him be the good guy. 

I'd like to use this column to pass 
on trips from travellers to intending 
ones, so please let me hear from you. 

For those going to London, 
England, the two meter repeater re- 
ported to be there is actually in 
Cambridge, More about that next 

time. 

G3ZCZ 



INDXA NEWS 



INDXANEWS LETTER 
From THE OXERS MAGAZINE 

During the past 2% years indxa has 
been associated with a few expedi- 
tions. I define a DXpedition as one or 
more hams going to a specific place at 
a specific time for the sole purpose of 
making as many QSOs as possible in a 
time span of 2 days to maybe two 
weeks. Below are shown the result of 
a few of the operations, 



that the results are about what you 

would expect, but the weight to be 
attached to each factor is not so 
evident, Le,, is it better to have more 
operators, or one operator with a 
beam (considered to be synonymous 
with a stronger signal). In my ex- 
perience with planning and working 
expeditions (I have never been on 
one) the following factors emerge: 

1. By far the most important factor is 
to have a good signal into whatever 
area of the world is being worked. 
This outweighs all other factors for 
the simple reason that if the callers 
can't hear the DX they don't know 
when to call and when to shut up. If 
you have ever heard OD5BZ working 
transceive and making 200 QSOs per 
hour you know what I mean. He was 
40 over everywhere. DXpeditions 
should use beams no matter what else 
am t. 

2. The skill of the operator(s) is next 
Courteous but firm, produces the best 
results. Outright nastiness produces 
more of the same and trying to 
accommodate everyone at the same 
time produces chaos* 

3. Split frequency falls third in im- 
portance in my opinion. It helps a 
great deal of course, especially in the 
first hours of operation when the 
DXpeditioners are trying to get rid of 
the first two thousand big signal Ws 
and about 500 DX headhunters. After 
that its importance goes way down. 

4. There is a strong tendency to forget 
most of the big guns have mixed 
totals, i.e., both phone and CW. A 
good CW operator can still run rings 
around a phone operator. In other 
words, the number of satisfied cus- 
tomers goes way up when a good CW 
operator is on the DXpedition. 

5. After the above items, lots of things 
enter into the total QSOs. The time 
spent operating is obviously germane. 
About 12 kilo QSOs will wipe out any 
place. That means 2 operators 
operating 4 hours on and 4 off for 6 
days, alternating phone and CW. 

6. The bands operated should be 
considered. Twenty is still the work 
horse, followed closely by fifteen. Ten 
meters is great for a few hours a day. 
The low bands should be used only to 
accommodate the 200 or so guys 
working for 5BDXCC. Really there 
are surprisingly few of them, I have 
never seen any DXpedition for which 
I QSL work more than 120 stations 



Place 


Duration 


No. Ops 


No. QSOs 


Remarks 


Palmyra 


1 week 


1 


1600 


Transceive-murder 


E. Pakistan 


4 days 


1 


800 


Transceive di pole 


Dominica 


4 days 


1 


3600 


Split-beam, ssb/cw 


Norfolk 


2 weeks 


1 


10,000 


Split-beam ssb/cw 


Willis Is. 


6 days 


5 


10,500 


Multi split-beam 


Bajo Nuevo 


3 days 


4 


4200 


Split-hurricane 


San Felix 


314 days 


2 


7000 


Split-beam 



on 80 and 40 and most of those did 
not request a QSL The number of 
topbanders you can count on both 
hands and no toes. 

In summary, one or two guys going 
to a rare one, operating transceive 
with a vertical, produces frayed 
nerves, frustrations, and a barrel of 
fun. Us big gun, big signal, persever- 
ing, skillful operators get through any- 
how. Heh, heh, heh. You peasants 
wait for the multi-op, split to linear to 
beam operation and you might make 
it. 

Not that it has anything to do with 
conducting DXpeditions, but you 
might be interested in knowing about 
QSLs resulting therefrom. 8000 QSOI 

will produce about 1500 requested 
the first week, another 1500 in the 
next two months, another 1500 in the 
next six months and a total of about 
5000 in 18 months. The rarity of the 
operation does not seem to make 
much difference in the total requests. 
The green stamps will total ebout 
$350 and nearly all of it will be in the 
first 1 500 cards. So you see 1 got it all 
figured. I'm gonna go to Clipperton, 
work those first 1500 and quit. 

K3RLY 




From the above data you can see 



Harry Simpson A4SCF 
c/o 73 Magazine 
Peterborough NH 03458 

Due to the lead-time necessary for 
publishing a national magazine, I am 
something like the moth — living in 
bathing suits in the winter and fur 
coats in summer! While still untang- 
ling the loose ends of last year, I must 
concentrate on new plans for making 
1973 a banner year for all concerned 
with the various MARS programs! Let 
me begin with an apology for the 
delay in answering some of your 
letters, When Alice and I returned 
from our extended vacation we were 
presented with a stack of more than 
two hundred individual letters re- 
questing MARS information! This, of 
course, in addition to our regular 
correspondence which normally runs 
about ten letters per day. 

After the apology - thanks! Not 
only thanks to those of you who 
requested the information — but to 



JANUARY 1973 



15 




those wonderful members of Air 
Force and Navy-Marine corps MARS 
who volunteered information on their 
programs - I don't know what I said 
to bring on such a response — but I'm 
glad! For the first time since the 
beginning of this monthly effort I 
have actual proof that there are other 
programs than Army MARS! 

First, a letter from W4NGU/3 with 
an outstanding proposal for CAP-Air 
Force MARS Coordination; next a 
friendly letter from Navy MARS 
member N0RRN (WB5AWA) listing 
these frequencies and times: 
Transcontinental RTTY Traffic Net: 

13,975 kHz, 100 wprn, about 11 
AM CST 

Eighth District Nets: 

7375 kHz, SSB-CW, 24 hours 
7495 kHz, RTTY, 60 wprn, 2300Z 
4010 kHz, Louisiana Traffic Net, 

0100Z daily 

He also included a copy of DNC 8 
(A), Mission and Policy — more about 
that later, 

A Navy MARSgram from Canal 
Zone Area Coordinator N0GCZ: 
Canal Zone Navy MARS activity on 
upswing with daily circuits to the 
United States on TTY, CW and SSB. 
Phone patches will soon be routine 
but message traffic is our current 
speciality. If you want to send a 
message to the Canal Zone any MARS 
station should be able to route it. Two 
meter activity is also growing. 

The message was forwarded by New 
Hampshire and Vermont Coordinator 
N0GBF, Karl W + Miles, Pesd Hill 
Road, Wilton NH 03086. Another 
very nice letter from Bill Karabinus 
WA6RAM/N0QMY, listing west coast 
frequencies and times, and iniro 
ducing 11th NAVMARCORMARS 
District Director Jack Hughes, 937 
North Harbor Drive, San Diego CA 
92132 — who can give full informa 
tion on the program in that area. 

AF7EJD, AFB0GSY and 
AFC4DTY alt wrote very nice letters 
introducing Air Force Public Affairs 
Coordinator J. Harvey McCoy 
AF2IYX, 109 Willow Ave. Hunting- 
ton NY 11743. Each gentleman added 
other information which will be 
passed along to you in the future. 
Finally, a letter from a fellow Army 
MARS member AD9SKU, Bob 
Ruggley of Cicero II, with many kind 
words about our eff forts - and, of all 
things - he enclosed eight (count *em) 
8-cent stamps to help out on our 
expenses! A feller like that should be 
rewarded, so I'm going to use one of 
the stamps to return the others! 

It was a tough struggle, but we're 
finally off the ground, with contacts 
made for information from each of 
the MARS services. The mail has all 
been answered, the sun is shining, and 
."ill is right with the world! If you need 



information about Army, Navy- 
Marine Corps or Air Force MARS, I 
am now in an excellent position to 
supply it, and I promise to answer all 
letters promptly -at least until next 
vacation! Sincere thanks to each of 
you who took the time and effort to 
write — may your New Year be the 
best ever! 

A4SCF 




A WORRIED COMPETITOR? 

Contrary to all the rumors, 73 has 
NOT annexed the telephone com- 
pany. Even with the tremendous 
growth we have been experiencing, 
the task of doing such a thing is 
beyond our means . , , for a white. 

But Ma Bell is worried! Not only 
have they started published a special 
interest magazine (see above), but 
their cover gives you that something- 
looks-awfully-familiar feeling. In addi- 
tion, we recently received a copy of a 
top-secret executive memorandum cal- 
ling for a dispatch of agents whose 
missions were to bring back FM and 
IC construction projects! (We won- 
dered why that last visitor had such a 
questioning look on his face when he 
heard the word "antenna.") 

In the face of all this we will make 
a prediction; Not only wiM we stand 
to meet the challenge that has been 
made — you can be assured that the 
second issue of this preposterous pub- 
lication will never meet the presses* 



73 GOES METRIC 



Now that the U of S has decided to 
go metric, the very least 73 can do is 
try to keep up - and perhaps prod the 
other ham magazines into following 
suit — as they did with the acceptance 
of the IEEE standards, etc. 

Besides that, we are already partly 
converted to metrrcity - right? Not 
too many of us have been active on 
the 250 foot band lately, though 



many are busy on the better known 
75 meter band. Ditto the 70 footer, 
popularly designated 20 meters. 

It will take a while before all of our 
articles are settled into the new no- 
menclature, but we'll try to convert as 
quickly as we can. Oh, there will be 
some areas that will take a while — 
like the 6-32 screw and its compatri- 
ots. That 32 represents 32 threads per 
inch - and in cement mixers that 
comes to about 12.6 and that is not 
going to be popular. Do you suppose 
the day will come when we do shift to 
metric threads? Or even metric heads? 

REMEMBER: 

1 In - 2.540 cm 
1 cm - 0,3937 in 







The Hamburglar 

STRIKES AGAIN f 

Milton L Mitchel K5LKL lost out 
to a bit of unethical Christmas shop- 
ping last month. The Cloaked Ciaus 
walked off with an Eimac AF 68 Sen 
No. 10888, Eimac PMR 8 Sen No. 
10918, and a Ml 070 power supply. 
An RCA model AR88 with a non- 
standard S-meter was also taken. 
Please contact Milton at Section A ( 
V«A Center, Temple TX 76501. 

A Trio TR2200 Ser. No. 241969 
was also politely lifted from the 
locked automobile of Ed Pores 
WA22BV. Anyone with information 
can reach Ed at 16 Dorchester Drive, 
Manhasset NY 11030. 



YaesuFT 101 No, 107036 
Standard 2m FM No, 102703 
Drake ML 2 No, 20189 
Standard SRC SQ6M 

No. 009210 
Aerotona 6IV1 355 LT. 

No. 685064 



Standard SRC 806M 
No. T 02703 



WA2YSW 4/72 

W6NPV 4/72 

WB2LLfl 4/72 

K1TLP 572 

RR Police 5/72 

Grd.Ctrl.TTml. 

NYC 



Lafayette HA 410 

No 009210 
Coll = 62S1 No T072A 

WRL Duo Bndr G010AT302 

HH2A t IT chan,. 04-07152 
SwanCygnei 270 p No. 313022 
Collins Mic, Mod. MMs 
No. 4294 

Heath HW-100& AC PS WA2JGP 

Swan 270B No IV! 39543Q WflHST 



C MathiM 5/72 
3234COrorwtdo Ave 
Imper iai Beach CA 



VYA2KOG 
MSU ARC 

E.Lrfnung Ml 
WA6FCY 

WA1NVC 
K4ACJ 

K4ACJ 



5 72 
ft 72 

6/72 

9.72 
972 
9/72 

10/72 
11/72 



16 



73 MAGAZINE 




1 1 



** 



Hello, "You-AH", looks tike it will 

be me running this column and 

the WTW Award from this date on. 

Let me introduce myself: 

Name: Gus M. Browning 

Call: W4BPD {and have signed well 

over 165 other calls from DX 

locations overseas, 
Been A DXer since - Nov, 25, 1927 
QSO*s made: Total over 600 t 000 
DXCC Nr. 4 P WAZ Nr. 40, and lots 
of the other awards not all can be 
remembered. 

Occupations: Editor & Publisher 
of The DXers Magazine, printer 
and Electronic Repair Shop, 

Thats enough tooting my own horn. 
Plenty of time at later dates I 

I need all the good, reliable DX 
tidbits, news, DXpedition plans, 
DX QSL info, and even any good 
photographs (in black and white 
- when possible) you may happen 
to have or get later on - They will 
to returned to you if you wMI 
mention "return to ??? on the 
back side of them. 

You can send your info to me 
either at the address of this mag- 
azine or (to save time) send it to 
me direct at this address: 

Gus M. Browning, W4BPD 

Drawer "DX" 

Cordova, S.C. 29039 
Or if you run across something 
that's red hot" and you think is 
important enough you could call 
me (please NOT COLLECT) at: 

(803) 534-6485 
You can call me anytime of day or 
night (as late as 2 o'clock A.M, - 
local time - I work that late every 
night here - 7 nights per week). 
In submitting info to me please 
keep in mind that I will have to 
have the news items in my hand 
no later than 3 days before the 
first of each month. This is being 
prepared on October 28th. as an 
example of how long before [t 
appears in your magazine. 

In case you havent heard yet, the 
year 1973 is being called "our 
year* 1 by 73 magazine so Wayne 
(the "big boss") and I have come 
up with an award to celebrate, an 
award not too hard to make. All 
you have gotta do is to work 73 
different countries in the first 73 
days of 1973, We will call this 
something like *The 73 - 73 - 73 
DX Award. So get the old rig 
ready to start on Jan, 1st, 1973. 
After you have worked your 73 
different countries in the first 73 
days of 1973 (thats the 14th of 
March) get three other hams to 
certify your log) send us the fist 
of stations you worked, giving the 
dates and times, etc. of the QSO's. 
The Award may be either a nice 
certificate or lapel pin, maybe it 
will have a small "cost" tacked on 
to cover our cost or maybe even 
free (if Wayne can afford to lose 
on the whole thing [). Will let 



you know well in advance of the 
March 14th. 

Future DXpeditioneers, prepare for 
all events* because you will have 
certain troubles" (other than the 
usual licenseing, customs, etc.) You 
will have QSL problems when you 
are back home, you will have a lot 
of such items as, time wrong, band 
wrong, even the mode and band 
will be wrong. Then you may have 
a "pirate" working the fellows at 
the same dates you are on. some- 
times a few days before or after 
you are on. Be sure you have a 
good GMT watch or clock and set 
it right and be sure of your GMT 
date (this also goes for those back 
here working the DX stations, too). 
All the above came to mind when I 
received a letter from Jim, K9TZH 
after his operation at Market Reef, 
where he operated as OJ0 SUF. 
A portion of the letter quoted: 

"OJ0 SUF QSL INFO: Fellows 
I am very sorry that there has been 
such confusion regarding the Market 
Reef Expedition QSL s. When I 
left Finland, all was in order but 
since that time , problems have devel- 
oped concerning financing the 6000 
cards. Have just received a letter 
from OH2BHU, who stated that 
the cards have finally been ordered 
and will be coming out very soon. 
Anyone having problems getting 
a card for their QSO f please write 
me and I will do everything in my 
power to get the contact confirmed. 
This includes fellows who have 
received their own cards back mark- 
ed "Not in Log". 

I would like to emphasize this is 
not a request for $ !" 
Jim says in the letter, "if I had 
only knew then, what I know now", 
after mentioning other problems. 
NOW FOR THE WTW AWARD 
At the present moment all the info 
and present status of the WTW is in 
the hands of Dave, K2AGZ and I 
am QRX for him to send all the 
info, etc. down here so that I can 
arrange it all in the files and then 
get going on the project again. I 
hope to soon receive this all from 
Dave and get going again. I suggest 
that all confirmations be sent to 
me direct instead of to 73 Mag, 
It will be more quickly handled 
and be less chance of your cards 
being lost, etc. I do very strongly 
suggest that you send your cards 
by "certified ' (cheaper), or via 
Registered mail and include enough 
(either stamps or money) to return 
your cards by "certified mail' plus 
of course the usual parcel post 
costs and naturally the WTW fee 
of One Dollar (to partly cover our 
costs). Be sure to list every card rn 
the order they appear in the DXCC 
country list, giving date, etc. of the 
contact. Remember we will keep 
this list you send us. You had 
better make yourself up a duplicate 
list to keep for reference purposes 
at later dates when you add new 
countries to your standing in the 
WTW. Remember there are three 
awards, the WTW* 100, WTW-200 
and WTW- 300 and these can be 
earned on CW and then the same 
for all PHONE. Will be telling you 



more about this from time to time. 
We are thinking about maybe 
giving nice Lapel Pins for the 200 
and 300 plateaus of our WTW. I 
wonder when the ARRL will start 
something like this, too 7 And 
while I am "wondering", why not 
also wonder about the overall view- 
point of DXing in general ? For 
instance, why not more countries t 9 
YES that's what I said "more coun- 
tries" ! I have not met ^nyon& yet 
who really has complained that 
there are "too many now". This 
word "countries" are used very 
loosely when refering to our DX 
awards. Except WTW, which stands 
for Worked The World, certainly a 
more descriptive group of words 
when talking about our kind of DX. 
I think it's time for Big Brother, 
the ARRL to do something about 
their DX Award set-up, give some 
pins for the 200 and 300 brackets, 
give us some new countries, cut 
that 250 miles separation between 
islands for a starter * OR - better 
yet -START SOMETHING BRAND 
NEW. (all of which I doubt they 
will do.) With computers being 
used these days even by some of my 
small grocery stores, I am sure that 
this could be done at a very reason- 
able price. They of course would 
be able to use the computer in 
many other ways when it is put in. 
This is nearly 1973 (73 Magazine's) 
and times are changeing rapidly and 
I think ARRL will have to do the 
same to "keep up to date" with 
the rapidly changeing world I 

I know that I will receive many 
letters telling me to not "rock the 
boat", you can't fight the establish- 
ment, etc. My answer to these is all 
the same t Ole Buddy, you have 
your ideas and f have mine and if 
you want to "air" your ideas we 
have the "LETTERS" page in 73 
for you to use (I also have "Letters 
to the editor" page or pages (if 
necessary in my little DXers Mag.) 
They are yours to use to let trie 
other fellow have your viewpoints, 
All I want to do is to have MORE 
DX for the boys to chase, giving 
them something to do these long 
winter nights coming on us now. 

I wonder if there are still some of 
you out there that have not yet 
tried makeing some of these new 
"gadgets" using these new IC's ? 
It took me ONE HOUR to build a 
very FB 10 meter pre-amp using a 
Motorola type 1590G and it gave a 
50 db gain with less noise than I 
could hear from my Collins 32S-3, 
Have built up a number of very FB 
other little "goodies" (quite useful, 
"gadgets".) All which will get 
you started with Solid State, you 
may as well face it fellows, solid 
state is with us and the days of hot, 
noisy, inefficient, etc. is about over. 
You are never too old to learn !! 
73 Magazine will give you plenty 
of these little "goodies" to build. 
Try a few of tnem and the Old 
Bug will bite you again and you 
will again become a ham like you 
used to be ! - Remember ?? 
That's it for this month, 

73 es DX, de Ai*dU BPD 



JANUARY 1973 



T7 



SSTV 
PROGRAM 



Presented by John Smith K3SLJ. 














A^f£ 



SOCIAL/ 

IEVENT&/ 



TT ' 



CONTESTS 



CONTEST EDITOR NEEDED! 

There is another aspect of amateur 
radio that we would like to cover 
regularly in the 73 newspages — con- 
tests and certificates. It is possible 
that we might be receptive if someone 
who was seriously into these things 
offered to keep the 73 readership 
informed. 

We might even be able to add some 
pecuniary interest to your amateur 
radio hobby. 

If you have better than average 
connections on keeping up with 
certificates and awards, and are inter- 
ested in preparing capsule facts on 
them for the 73 newspages, drop a 
line to us. 

Ditto contests. Readers would like 
to know what contests are being run, 
when and enough data to get started 
in them or send for full rules. We do 
want to leave CO as the force for 
exhaustive details on contests and just 
bring a synopsis to 73, Anyone with 
good bona fides interested? 

3RD WORLDWIDE SSTV 
CONTEST 

The third worldwide contest for 
SSTVers is being sponsored by cq 
electronoca Magazine, The operating 
times are 1500-2200 GMT Feb. 10, 
and 0700-1400 GMT Feb. 18. Plan 
to use all authorized frequencies on 
80 through 10 meters. Each two-way 
exchange counts one point with a 
multiplier of 10 for each continent 
and an additional multiplier of 5 for 
each official ARRL country. The only 
exception is that each VE and W call 
area will count as a separate country. 

Logs must contains Time (GMT), 
Frequencies, Data, Call sign, No. sent 
and received, Country multipliers, 
Points and final score. They must be 
received by Prof. Franco Fanti, via A* 
Dallolio 19, 40139 Bologna Italy be- 
fore March 20, 1973. 

NOTE: All contacts must be made 
via SSTV only. Use of any other mode 
of transmission before, during or after 
the Slow Scan exchange is not permit- 
ted, and will cause your log to become 
invalidated. 

VHF CONTEST 

Worlwide VHF Activity 
1973 -3PM local March 10 to 10PM 
local March 11. Purpose: To keep 
VHF bands active, allow rig testing, 



LIFET1MK CANCELLATION \* ARD 



• rss 






Be it known by these presents that . . 

has provided satisfactory proof to the staff of 7 A MAG AZIINE 

thai »h A .n invtf lniat* schmuck inrt !u»» no buiinw wnHmq Ihe mffguiM. In Oftfe 10 prmnl, to th* bWT ot 111* 
•Willy of Itw Hfff ot 73, flhcvf mid wJhmiick tyMl ffHtity c D pi« Of 73 Mis Itffl i>l J3 *'H P>«*» bvb^ flOM-h^ *lfar1 
to ame»l my irtd all mtacrvtimt no* on Itit *hAi *ri r*« prominently poti in Ihp n offteaiuid **fTHK*t*l n«M 
and cjil l* pnvwiT. rt ■" CWV. *m ptokihlr lulwt subscription! K> 73 MlflMini HiNfvd-WtTly being | 
MimKWJ In ndaiUtti » •*»« =*d "ia*w*« to pinvrvi the store Khmuck item gtiung iub»cri&Tion cwmm 
ol 13 Umt*itrw. **/ cnvriau* nafv^pr a* 1h* ^«^<m «ffl b*d*f*cW to m>k* #v*iy ftowblr rfrQrt to 
rtwt *a iiininiijiinml fit 73 wv *w*4*i* M ffw inwnw&tr nw yl faJ rtiOOJ ol wd »£hrt«cfc i domic** C* 
l hi tM«w I 



ft -: 



W w 



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■W">r, 



NEW CERTIFICATE AVAILABLE 

Now and then - it certainly doesn't happen often - but occasionally 
someone of particularly low moral turpitude manages to become a subscriber 
to 73. The Lifetime cancellation award is reserved for those who, by their 
rottenness, richly deserve it. 

None have yet been issued; however several amateurs are definitely up 
for serious consideration. Unless psychiatrists are able to give them 
emergency mental repairs, these sick-o's will be early winners. 



allow hams to get acquainted with 
fellow VHFers. Exchange call letters, 
county and state. Count contacts with 
mobiles in each county worked. 
Mobiles can work a station once from 
each county of mobile or portable 
operation. Let's see some mobiles. 
Scoring: Multiply number of contacts 
times number of counties worked 
times number of states worked. 
Awards: Certificate to each station 
scoring 100 points on six or 50 points 
on two meters. Certificate to the top 
station in each state regardless of 
score. This applies to each band of 
operation. Each band is a separate 
entry and a station can enter one or 
both bands. Logs should show time 
band mode and exchange info. IVIail 
logs by April 15 to WA3NUL, Box 
1062, Hagerstown MD 21740, 

WH EATON HAMFEST 

The Wheaton Community Radio 
Amateurs will hold their 11th annual 
Mid-Wanter Swap and Shop on Sun- 
day, February 11, 1973 at the DuPage 
County Fairgrounds, Wheaton, 
Illinois. Hours: 8:00 AM to 5:00 PM. 
Si .00 Advance/Si. 50 at the door. We 
are expanding to two buildings this 
year. Refreshments and unlimited 
parking. Bring your own tables. Free 
coffee and donuts 9:00 - 9:30AM 
Hams, CB'ers, electronic hobbyists, 
friends and commercial exhibitors are 



cordially invited. Write W.C.R.A., Bill 
Rambox, WB9AVD, P.O. Box OSL, 
Wheaton, Illinois 60187 for informa- 
tion. 

TROPICAL HAMBOREE 

Announcing the upcoming Tropical 
Hamboree/ARRL Southeastern Di- 
vision Convention Jan 20—21, 1973, 
at Miami Municipal Auditorium, 499 
Biscayne Boulevard, Miami, Florida. 
Further information may be obtained 
from Evelyn D, Gauzens, W4WYR, 
Chairman, c/o Dade Radio Club, P.O. 
Box 73, Biscayne Annex, Miami, 
Florida 33152. 

BRISTOL 73 ACTIVITY 
CONTEST AND AWARD 

Contest to run from 1st January 
1973 to 31st August 1973, and is 
open to all licensed radio amateurs in 
the world, who are invited to make 
contact with Bristol, England, Bristol 
is defined as within Postal Districts 1 
to 20 inclusive (BS1 to BS20J. 

A case of sherry donated by a 
famous firm of Bristol wine merchants 
will be presented to: 

1. The highest scoring station outside 
the ILK. call areas. 

2. The highest scoring station within 
the U.K. call areas but outside Bristol. 

3. The Bristol station making the lar- 
gest number of contacts with partici- 
pating stations, 



JANUARY 1973 



19 



COLLINS UPDATE 



To cover the new phone 
frequencies without having to switch 
down to the next lower 200 kHz 
segment on your rig, replace your hf 
oscillator crystals with the following: 
80M-6855 kHz, 40M~ 10255 kHz. This 
will allow you to tune 200 kHz 
segments of 3700-3900 kHz and 
7100-7300 kHz. Thanks to W4NJF. 



.52 SIMPLEX? 

The IRC bulletin announced the 
topic of .94 repeaters with the head- 
ing "KA-BAM!" And that's about 
what happened at the council meeting 
October 15, T972, at Michigan City. 
Many points about the pros and cons 
of .94 repeaters were brought out, and 
opposing viewpoints were heard from 
simplex and repeater operators alike. 
It might be best said that no one 
really knows the ultimate solution, but 
the Council has voted to endorse .52 
as the national calling frequency (as 
have other states), and -46 as the 
Indiana spx. channel to be used as an 
alternative to .52 and for emergencies. 
While this does not solve the .94 
problem, it at least takes the pressure 
off the Council to act in a negative 
direction, and is a hint to simplexers 
that ,52 and .46 are good alternative 
choices to ,94, 




% 






What a way to install an antenna! This 
Wilson Beam was recently installed by Peter 
Williamson in Augusta, Maine. He reportedly 
had to remove a tree for complete clearance. 
What did he use for that . , , dynamite? 
(Kennebec Journal photo by Veilleux) 




TRANSMITTER ON A CHIP 




*im hi 



Someone eventually had to do 
it — and they did. Lithic Systems has 
announced a complete AM transmitter 
on a tiny IC chip, Designated the 
LP2000, it is capable of 50 MW 
output on 10 meters when fed by a 
12V supply. Operation on 6 meters is 
also possible with slightly reduced 
output. 

The block diagram shows that the 
chip isn't a simple oscillator/ 
modulator as you might expect. Not 
only does it have two buffer stages 
between the oscillator and output 
stage, but it incorporates a power 
supply regulator and an audio preamp 
that is sensitive enough to be driven 
by a small speaker voice coil. Pretty 
sophisticated for an AM transmitter! 
T/R switching is accomplished by a 
latch trigge r so the circuit can remain 
connected to its power source at all 
times. 



■■>»«■' 







nmurr 



■nnt^ftflii 



Fig, 1, Schematic of the complete transmitter. 

You can't put everything on a chip 
(yet), so naturally a few extra com- 
ponents are needed to get things 
working. Not many though — two 
coils, an overtone crystal, two resis- 
tors and a few capacitors — no trouble 
should be had by anyone trying to 
package the circuit in weird places 
(like your wristwatch . . .or an 
enemy's ham sandwich!). No kidding, 
this little transmitter is bound to start 
showing up everywhere as a bug. 
Another possibility is a remote burglar 
alarm small enough to mount right 
inside a door knob! Power require- 



ments are +5 to -H5V so those tiny, 
aspirin-size batteries are a natural for 
the power source. Current drain at 
12V is 28 mA, 

Lithic Systems is hard at work 
developing VHF FM and even SSB 
transmitters similar to this one. Those 
are certainly going to revolutionize 
things. Who is going to manufacture 
the first 2 meter FM name plate? 

Contact Circuit Specialists, Box 
3047, Scottsdaie AZ 85257 or watch 
their ads. 

POWERHOUSE 




The ALPHA 77 has got to be the 
linear for the discriminating amateur 
who demands quality and perfection 
for his si;ack. It is not just an ordinary 
linear built for ordinary ham use. It 
features heavy duty construction and 
is designed to operate at 3000 watts 
PEP phone input on a continuous 
duty basis. At the legaf limit of 2000 
watts (taking into consideration the 
intermittent type of service that oc- 
curs in the normal SSB operation) this 
amplifier is practically snoozing. 

It employs a single Eimac 
8877/3CX 1 500A7 ceramic-metal, 
grounded-grid triode that is air cooled 
by a computer grade thermostatically 
controlled blower. This tube has a 
rated dissipation of 1500 watts and 
can be driven to the limit for ham use 
by only 50 watts of drive. This makes 
it compatible with practically any 
exciter on the market 

The overall design stresses safety 
and sensible operation. When turned 
on, a step-starting relay system gradu- 
ally applies power to prevent current 
surges and relay arcing. To keep every- 
thing in check while operating, full 
metering is provided. Besides the 10A 
meter for continuous monitoring of 
plate current, a second meter can be 
switched to read plate voltage, grid 
current, and forward or reverse rf 
power output. Yes , , . the ALPHA 77 
has a built-in direct reading 0-5000W 
wattmeter! An additional feature is 
the grid excess current circuitry. The 
grid relay automatically kicks out 
when the final tube is either over- 
driven or underloaded. Besides assur- 
ing full tube life, the relay also protects 
against accidental flat-topping and a 
possible blown input circuit, 

Continued on page 136, 






20 



73 MAGAZINE 




AND THE 



RADIO 




A. Prose Walker, Chief 

Amateur and Citizens Division 
Federal Communications Commission 

Mr. Walker's speech was given be- 
fore the Pacific Division Convention, 
ARRL, October 15, 1972 at San 
Mateo, CA, and at the Southwestern 
Division Convention, ARRL, October 
21, 1972, at Santa Maria CA. 



Although there are many other 
subjects of immediate importance to 

amateurs, I would like to discuss 
today the question of the allocation 
of amateur bands. There is no more 
urgent and time-consuming task, in 
my opinion, than this one. And al- 
though the mechanics of the next step 
in the process have not yet been 
brought out into the open, that is no 
reason not to begin our preparation 
for what could be the greatest oppor- 
tunity amateur radio will have in your 
lifetime and mine to obtain additional 
amateur bands in the HF region from 
3-30 MHz. 

We are not yet at the point where 
any phase of amateur radio can be 
substituted for the activity handled on 
a daily basis on our main bands from 
80 through 10 meters. Tm not sure 
that any phase could or should be a 
substitute for this. If those bands were 
taken away, we might or might not 
survive. For as long as I have been an 
amateur, the philosophy of our ap- 
proach to allocation conferences has 
been primarily one of defense of our 
existing bands; essentially a negative 
philosophy. 

Over the years, our allocated bands 
have been gradually whittled away: 

160 meters taken away as an emer- 
gency war measure 31 years ago and 
returned only in minute amounts 
since then; 

Eighty meters shared with broad- 
casting, fixed and mobile and except 
in Region 2, drastically reduced in 
width as an amateur band. 

Forty meters has become such a 
shambles of its former self that it is 
hardly recognizable anymore as an 
amateur band ... as indeed it is NOT 
except during certain times of the 
day and seasons of the year and 
sunspot cycle. We have 300 kHz to 
use, if we can, but the rest of the 



world has only 100 kHz "exclusively 
amateur/' Listen some morning, 
wherever you live, and see how "ex- 
clusively amateur" it is from 
7000-7100 kHz. 

In 1947 at Atlantic City we lost the 
top 50 kHz of our twenty meter band 
to the Fixed Service, and in certain 
countries of the world they also use 
from 14250-14360 officially and 

other parts of the band, unofficially, 
Fifteen meters is definitely a PLUS 

on our side but it hardly makes up for 
all the other minuses we have incurred 
over the years ... we got the eleven 
meter band and then lost it to the 
Citizens Radio Service, 

Ten meters is probably in reason- 
ably good shape, but we did lose the 
top 300 kHz at Geneva in 1959, 
primarily to the meteorological service 
for their high altitude weather bal 
loons. 

The World Administrative Radio 
Conference (WARC) held in 1959 was 
the last one to deal with the allocation 
of the HF spectrum on behalf of all 
the various services. There have been 
individual service conferences since 
then, but they have not been em- 
powered to re-allocate or reassign ex- 
cept within the bands of frequencies 
already in the table of allocation 
contained in the International Radio 
Regulations. The head of the United 
States delegation to the 1959 confer- 
ence was the late FCC Commissioner T. 
A. IV1. Craven, an engineering expert 
who had grown up with the telecom- 
munication industry. He was not an 
amateur himself, but he had asso- 
ciated with many throughout his 
career. He had a keen understanding 
of the value of amateur radio to our 
country. It is a tribute to Commission- 
er Craven that the amateur service 
fared as well at that conference as it 
did. We might well have lost 200 kHz 



of 40 meters, and 240 kHz of 80 
meters, had it not been for his fore- 
sight in handling the negotiations on 
those bands. 

I hope that by now, you and I are 
in the same situation as the farmer 
and the mule which he had to hit 
across the head with a two by four in 
order to get his attention. If I have 
your attention, let me discuss with 
you my appraisal of the frequency 
allocation picture for the Amateur 
Service. I shall go into detail how 
frequencies are obtained and what 
should be expected of amateurs when- 
ever a reallocation conference is called 
by the ITU, I shall predict the ama- 
teur population by 1980 and the 
amount of spectrum that will be 
required to accommodate them. If I 
seem to lend a measure of urgency to 
the subject, it is intentional, because 1 
believe the subject is terribly impor- 
tant to atnateur radio worldwide. If I 
can convince you, perhaps through 
your agreement , you can initiate ap- 
propriate action through your repre- 
sentatives. 

A short time ago we were asked to 
predict the number of amateur sta- 
tions in the world by the year 1980. 
This is difficult if for no other reason 
than the fact that we don't really 
know how many we have at present. 
Such figures are quite vague for cer- 
tain countries of the world, Also the 
prediction depends on the assump- 
tions you make as to what factors 
influence the growth and in what 
proportion. The factors are different 
in various countries, I won't attempt 
to go into detail We know that in 
certain countries there are rather start- 
ling increases in the number of ama- 
teur stations. We think we know what 
has brought about such increases, and 
what might do the same in our own 
country* Taking these aspects into 



JANUARY 1973 



21 



consideration and using some black 
magic, we arrived at a worldwide 
amateur population figure for 1980 of 
between 600,000 and 800,000, Even 
allowing for some discrepancy in these 
figures, it is obvious that if anywhere 
near that number of amateurs has 
access to our bands around 1980, 
particularly the HF bands, there is 
going to be much greater congestion 
than we have at present. Suppose we 
increased the amateur population of 
just the United States by around 50%, 
what do you think the bands would 
sound like on a weekend? Add to that 
figure another hundred thousand or so 
amateurs scattered around the world, 
and I think you will agree that we 
could have real QRM at peak opera- 
ting hours. Please don't draw any wild 
conclusions from this discussion that 
the FCC is about to do something 
drastic that will cause the growth of 
amateur stations to mushroom, as it 
did in the Citizens Radio Service from 
around 40 r 000 licensees in 1958 to a 
present total figure of about 815,000. 
The most obvious solution to any 
problem of frequency congestion is 
additional frequency space. Let's ex- 
amine what is involved. Do we say to 
the FCC, 

"We need more spectrum . . . 

how about assigning another W0 

kHz on the top end of twenty 

meters?" 
No, the FCC can't do that because 
this is an international problem that 
can be solved only through the l,T.U, 
The United States is one member 
administration of that body, What is 
the mechanism of getting our 100 
kHz? First a World Administrative 
Radio Conference must be called un- 
der the provisions spelled out in the 
Montreaux Convention. Is that apt to 
be done? I say yes, but don't ask me 
exactly when, But whenever it comes, 
we must be ready and that takes a 
long time. 

How do amateur frequency bands 
get established and put into the Table 
of Frequency Allocations? Member 
countries of the I.T.U. such as the 
United States, Australia, New 
Zealand, Japan, the Soviet Union, 
France and any others, submit pro- 
posals for utilization of any part of 
the spectrum under consideration. 
These proposals are determined ind- 
ividually by each country and submit 
ted in advance of the conference to 
the LT.U. At the conference, an allo- 
cation committee is formed, which is 
further divided into sub-committees 
to consider the previously submitted 
proposals for use of particular por- 
tions of the spectrum. 

You can readily understand that if 
a majority of the members of such a 
committee are in favor or against a 
proposal, its chances of success or 



failure are correspondingly equivalent. 
How do we get enough countries to 
agree with the amateurs 1 position 
seeking more allocations? We start 
well ahead of time and obtain con- 
currence of governments throughout 
the world prior to the conference, to 
include the spectrum needs of the 
Amateurs in their proposals to the 
I.T.U This certainly includes our own 
government which has consistently 
championed the cause of Amateur 
radio throughout the years. It also 
includes as many other countries as 
possible, because decisions are taken 
on the basis of a majority vote. 
Without support in committee and 
votes on the floor, the proposal fails 
of adoption. It's that simple. 

Is such an endeavor within the 
potential of radio amateurs? Again I 
say yes. It won't by easy, and there's 
no guarantee of success, But I keep 
repeating that we can't afford not to 
do it! If there was ever a golden 
opportunity for Amateurs to do some- 
thing about their HF allocations, 
NOW IS THE TIME. 

In all likelihood, there will be 
another WARC dealing with the HF 
spectrum within the current decade. If 
not, derogations of the Treaty may 
pre-empt portions of the spectrum 
before a conference can be called. 
Let's just assume that we might have 
one within the next 6 or 8 years. What 
should we do between now and then? 
Is it too soon to be stirring ourselves? 
I think not Let me tell you why. 

You all know, with the advent of 
satellites, what has transpired in tele- 
communication during the past de- 
cade. Many services are in the process 
of transferring their operations from 
the HF spectrum to the GHz spectrum 
of satellites or onto cables. Notable 
among these is the International Fixed 
Public Service which is transferring its 
operations about as fast as feasible. 
Others include the Maritime and Aero- 
nautical services in varying degrees. 
The reason, reliability. Who will oc- 
cupy the portions of the spectrum 
which inevitably will be vacated by 
many of the Fixed Service trans- 
mitters? Probably a host of users not 
yet evident will file claims on the 
spectrum, plus the many countries 
which still require HF because they 
have no cable terminal nor an earth 
station for satellite operation. Those 
who are successful in obtaining spec- 
trum space at the next WARC will be 
those who have prepared their posi- 
tions carefully with convincing justifi- 
cation ... a professional effort 
worthy of consideration at highest 
levels of government It won't be a 
"shoo-in/' believe me. Undoubtedly 
the HF broadcasters will be after 
additional space . . . something like 
ten bands 500 kHz wide. What should 



be amateur position be f both domes- 
tically and internationally? It has to 
be the same, because our HF bands all 
have long distance progation charac- 
teristics in vary ingdegrees depending on 
propagation phenomena. 

What I shall now propose is not an 
FCC plan, but one that 1 personally 
would suggest as a desirable approach. 
You may call it what you will, but I 
emphasize it has no sanction by the 
FCC. It has five major points. 

First, I urge that the amateur satel- 
lite program be expedited with the 
goal of having a near-synchronous, 
"semi -professional" amateur satellite 
in orbit during the early part of 1976. 
Without going into the many details 
involved, this could have a tremen- 
dous effect on many nations of the 
world, If you have the "bird" opera- 
tional, a team of competent amateurs 
with a portable earth station could 
travel to selected countries for demon- 
strations and educational purposes, 
bringing to their realization what ama- 
teur radio can do for them through 
their young people. Use of the ama- 
teur satellite would be a most drama- 
tic means of calling this to attention. 
Aside from the educational benefits of 
the satellite in amateur communi- 
cation, such a program would almost 
certainly make friends for the Ama- 
teur Service , . . something which we 
need desperately as evidenced at the 
last WAR-ST. I repeat, the ITU makes 
its decisions via the voting route, and 
the United States has 2 votes; one for 
the U.S. proper and one for the 
Territories, When the chips are down, 
it 's the votes that determine who gets 
what and how much! No majority in 
the voting, no allocation. 

Second, I would formulate a high 
frequency allocation program for our 
future needs, assuming that the pre- 
diction figures I mentioned earlier will 
prevail. In this let's not be mice, let's 
THINK BIG! Perhaps we won't get ail 
we want, but let it not be because we 
didn't try! 

a) Let's get 160 meters returned. 

b) Work out a program aimed at 
making the entire 3.5-4.0 MH2 band 
exclusively amateur, worldwide. 

c) Work closely with other users of 
the spectrum in the area of 7 MHz, 
especially the HF broadcasters, and 
make a tough, determined effort to 
not only unpollute our existing 40 
meter band, but expand it to encom- 
pass 7000—7500 kHz, exclusively 
amateur t worldwide. It's just possible 
that under some conditions, HF 
broadcasting would vacate our 40 
meter band, 

d) Go after a new exclusive amateur 
band from 10.5-1 1.0 MHz. 

e) Work for expansion of 20 meters 
up to 14.5 MHz on the high end, but 
at the very minimum attempt to 



22 



73 MAGAZINE 



obtain the return of the 50 kHz we 
lost in 1947 ... all of ft exclusively 
amateur. 

f) in the area of the spectrum from 
17-20 MHz there are 2.3 MHz now 
allocated to the Fixed Service* How 
about a new band in this area from 
1 7.5-18.0 M Hz? 

g) Although 21 MHz is not as critical 
as some others, at times it gets conges- 
ted- Why not try to expand it up to 
21,5 MHz on the high end. This would 
be at the expense of HF broadcasting, 
but they might agree to slide up the 
spectrum an equivalent amount. 

h) Jn the area above our 15 meter 
band, there is almost 2 MHz now 
allocated to the Fixed Service. Why 
not go after a band from 23.5—24.0 
MHz. 

I) Ten meters is wide enough and I 
woufd not suggest any further expan- 
sion there with the possible exception 
of getting back the 300 kHz we tost 
previously. 

If we could obtain the foregoing, we 
wouid have bands about every three 
MHz throughout most of the HF 
spectrum, and could follow the propa- 
gation curves as the MUF changes 
throughout the day and night. 

Third, we should be organizing a 
professional domestic, U.S. team to 
investigate and coordinate informa- 
tion on specific areas of the spectrum; 
analyze data that could be obtained 
on utilization of assigned allocations 
by the various services; dig out in- 
formation on new potential users of 
the HF spectrum that may not have 
come to the surface yet; prepare a 
professional position paper for use at 
the appropriate time within this coun- 
try; and work thoroughly, with the 
foregoing as a basis, throughout the 
preparation period when the position 
of the United States is being formu- 
lated. That time has not yet come, but 
when it does we should be ready to 
participate armed with proposals, 
facts, and figures, insofar as possible 
to get them, in support of our desires. 
That is the only way to deal with 
professional allocation people, who 
are notably lacking in sympathy when 
it comes to allocation of the spec- 
trum. 

Fourth, extraordinary effort should 
go into liaison and coordination of 
whatever program is agreed upon, 
with the most influential and impor- 
tant IARU member societies. The 
same goals, If proposed throughout 
the world on a coordinated basis 
could accomplish much more than a 
haphazard effort, no matter how well 
prepared the program might be. if 
even a dozen of the t25 countries 
which usually take part in such de- 
liberations* would propose the same 
program for amateur allocations ft 
wouid auger well for success. The 



important thing is to obtain each 

country's acceptance of the amateur 
position prior to submitting its nation- 
al proposals to the KTM. Usually, 
once a delegation gets to the confer- 
ence it is too late to change position. 
This simple statement of affairs is 
miles from its accomplishment. It 
would require at least one and perhaps 
several teams of people to travel 
throughout the world to explain and 
urge the adoption of the position to 
IARU people, and provide them with 
assistance in justifying the program to 
their own governments. No one but 
amateurs in individual countries can 
do that job. We have well known 
people in our ranks — use themf Maxi- 
mum assistance should be given them 
through prepared material which 
could form an equivalent basis for 
justification that we would use in this 
country, or modified as circumstances 
indicate desirable. Certainly condi- 
tions and viewpoints will undoubtedly 
be different in various countries of the 
world, but that should not dampen 
our effort, merely sharpen our per- 
spective. 

And finally, our selected group of 
amateur experts, professionals in tele- 
communication, should be our repre- 
sentatives at the WARC. As many as 
reasonable should attempt to be ap- 
pointed to their national delegations 
for purposes of liaison with their own 
governments. The composite team 
should be directed by someone with 
experience in international allocation 
matters, such as Tom Clarkson of New 
Zealand, ZL2AZ, so that a co- 
ordinated team effort can go into the 
conference work itself, in the commit- 
tee and subcommittee discussions, all 
on a professional level, to the credit of 
the Amateur Service. 

The program I have outlined may 
not be acceptable in all details to 
everyone, but at least it could be a 
beginning of the formulation of a 
program. It would take money. It 
would need professional manpower, ft 
would require time. And above all it 
would need confidence in the purpose 
of the effort, with sufficient desire to 
succeed and an understanding of the 
difficulties to not become discouraged 
when the going got rough. In my 
opinion, the result will be a measure 
of the amount of effort which the 
amateurs of the world are willing to 
put into it. There is no guarantee of 
success in any degree. But if we are 
ever to have a chance to obtain 
additional HF allocations, it seems to 
me the time to begin is NOW! 
You may well ask the question: 
"What is the alternative if we do 
not obtain additional spectrum 
space and our population ex- 
pands as predicted? 
There is no answer that any one 



individual can provide, and however it 
is answered it wouid have to go 
through rule making procedures of the 
Commission, But I think it is only 
logical to conclude that as the number 
of amateurs using wide- band emissions 
increases, something will have to be 
done to reduce the interference po- 
tential of amateur signals. There are 
several avenues of approach. One 
might be to reduce power in particular 
ways for various classes of stations. 
Another might be to reduce the occu- 
pied bandwidth, giving some kind of 
incentive to the signal which occupies 
the least practicable amount of the 
spectrum. Another would be to re- 
duce or eliminate wide-bandwidth 
emissions, or restrict them to the 
highest class licensees, as was formerly 
the case on 75 and 20 meter phone. 
We probably should encourage more 
CW even though many people con- 
sider that to be an archaic form of 
communication. But a CW signal occu- 
pies the least amount of spectrum and 
if we get too numerous for our exist- 
ing bands, as we now use them, it 
might be that CW wouid again become 
the primary mode of communication, 
rather than SSB. I might say that we 
well may be approaching this condi- 
tion now. Certainly we see no techno- 
logical breakthrough on the horizon 
which is of the same magnitude as the 
single-signal receiver of 40 years ago; 
or single sideband which was made 
popular shortly after WW-M or other 
development of like nature. 

I consider it my responsibility to 
have pointed these matters out to you 
today, and 1 urge serious considera- 
tion by your representatives of the 
proposed action. The talents among 
the amateur ranks are more than 
adequate to achieve the degree of 
professionalism required for this task, 
ft seems to me, that they must be 
sought out and used, not on the basis 
of winning a popularity contest but 
because they are professionals and 
therefore what they can do for ama- 
teur radio. 

The other day in doing some re- 
search on the evolution of spectrum 
management, which I shall discuss 
before the Radio Club of America in 
New York City, I ran across a state- 
ment which was used to describe the 
results achieved by the United States 
at the recent WARC-ST. It is so 
apropos to my thoughts on the sub- 
ject I have discussed that I would like 
to quote it here: 

"Although the United States went 
into the Conference with strong op- 
position to some of its proposals, the 
results were most favorable and 
proved the value of thorough prepara- 
tion, advance coordination and a dele- 
gation composed of experts in all 
facets of telecommunications. 



' r 



JANUARY 1973 



23 











TO END AMATEUR RADIO 



* 



The FCC almost got one by all of 
us! And this one is a beaut. This 
proposal would make it extremely 
difficult to put up a tower or a mast 
for your antenna. Anything over 20 
feet above your house would require a 
lot of paperwork, authorization, an 
okay from the neighbors — the works. 

The deadline for official comments 
has passed by r but we are asking for 
an extension of the comment time 
since this docket was not sent to us 
when it was released and amateurs 
have had no opportunity to see or 
consider the impact of this far reach- 
ing docket. 

I want to thank Steve Murray 
K1 KEC for bringing this corker to our 
attention. 

Read through the text, please. Talk 
about it at your club - and file a 
comment. Please, please file a corrv 
ment. Amateur radio comes under the 
Safety and Special Radio Services — 
so this docket means US! If this 
docket doesn't get you excited then 
you need some help to get you back 
to life again. It is so incredible that it 
seems like a bad dream - but it is here 
and it is about to be passed into law. 

PETITION: To extend the time for 
comments on Docket 19555 until 
February 28, 1973. 

This docket, which proposes 
profound changes in the whole fabric 
of amateur radio, has not been 
brought generally to the attention of 
radio amateurs and they have not had 
an opportunity to understand or 
comment on the docket. This is 
manifestly unfair. 

In order to permit the publication 
of the entire text of the docket and 
allow time for its delivery, reading, 
discussion and comment, much more 
time is needed. The next issue of the 

*A* wt now know it. 



amateur radio magazines in which the 

docket could be published would be 

received in January. This would make 

a cutoff date for comments of 

February 28, 1973 practical. 

Please extend the time for 

comments on this docket. 

FHed by Wayne Green 
W2MSD/1 

Docket No. 19555 

In the Matter of Implementation of 
the National Environmental Policy 
Act of 1969 — Notice of Proposed 
Rule Making — Adopted July 24 r 
1972; Released August f, 972 -By 
the Commission; Commissioner 
Johnson concurring in the result; 
Commissioner Hooks absent. 

1. Our purpose herein is to imple- 
ment the National Environmental 
Policy Act of 1969, 42 U.S.C.A. 
4321-4347, and particularly Section 
102(2»(c} of the Act 42 LLS.CA, 
4332{2){c). (Heretofore, the Commis- 
sion has considered environmental fac- 
tors on a case-by-case basis, pursuant 
to an initial policy judgment that this 
was the better and more appropriate 
means of implementing the statute, in 
view of the relatively limited environ- 
mental impact of Commission actions. 
Though we have not decided many 
cases in which environmental ques- 
tions were at issue, such questions 
have been considered when they were 
present. See, e.g., Amendment of FM 
Table of Assignments, 25 F.C.C. 877, 
1970. In the light of recent court 
decisions, however, we have reassessed 
our initial position and are now per- 
suaded that it is advisable and 
desirable to issue specific imple- 
menting regulations.) 

2. In drafting the rules, careful 
consideration has been given to Guide- 
lines issued by the Council on En- 
vironmental Quality. In its regulatory 



activities, the Commission approves or 
disapproves of applications which may 
involve construction projects by 
others which may have a significant 
effect on the quality of human envi- 
ronment, but does not itself engage in 
construction activities. In processing 
the hundreds of thousands of applica- 
tions which are filed during a given 
year, it is almost totally dependent on 
information furnished by the appli- 
cant and others. Whether the criterion 
is efficiency, practicality or fairness, it 
is preferable to have all of the infor- 
mation and arguments from all in- 
terested persons before a judgment is 
made. This is particularly true of 
many environmental considerations, 
which have only recently been 
introduced as factors in the de- 
cision-making process, Thus, we pro- 
pose (where there appears to be signi- 
ficant environmental effect) to trans- 
mit the application and related papers 
(including an environmental report 
prepared by the applicant) to the 
expert agencies, and to elicit environ- 
mental comments from those agencies 
and the public on the basis of those 
materials. A detailed environmental 
statement would be prepared follow- 
ing submission of agency and public 
comment. This seems to us the best 
way to assure full and fair considera- 
tion of the question of environmental 
impact. 

3. Our purpose has been to fully 
implement both the fetter and spirit 
of the environmental statute, consis- 
tent with procedural safeguards set 
out in the Administrative Procedure 
Act and the Communications Act, and 
with no greater application processing 
burden or delay than is necessary. The 
rules provide for the regular input of 
environmental data which will facili- 
tate the identification and considera- 



24 



73 MAGAZINE 



tion of environmentally significant 
factors. They provide for comment by 
interested individuals and organi- 
zations and by expert governmental 
agencies, and for their participation in 
Commission proceeding. They provide 
for the consideration of environ- 
mental factors at the same time and in 
the same way as other factors perti- 
nent to a public interest determina- 
tion are considered, except that they 
provide for the preparation of a "de- 
tailed environmental statement" fol- 
lowing comment by interested persons 
and expert agencies and prior to ac- 
tion, as required by the environmental 

3CX, 

4. The rules apply to applications 
involving construction. Attention is 
directed to the fact that the Com mis- 
sion has not for some years required 
applicants for authorizations in the 
Safety and Special Radio Services to 
file an application for authority to 
construct prior to construction of 
station facilities. See Section 319(d) 
oft the Communications Act, 47 
U.S.C. 319(d), In those services, there- 
fore, the proposed rules are made 
applicable to applicants and applica- 
tions for station authorizations rather 
than applications and applications for 
authority to construct. For the most 
part, it is anticipated that the approxi- 
mately 550,000 Safety and Special 
applications filed annually would in- 
volve minor construction having no 
significant environmental effect. How- 
ever, Safety and Special applicants 
should consider environmental factors 
prior to construction, since construc- 
tion without prior consideration of 
the environmental consequences and 
Commission authorization would 
prove fruitless if the Commission 
should subsequently find it necessary 
to deny the application for license on 
environmental grounds. 

5. Authority of the proposed rules 
is contained in Sections 4(i), 4<jJ, 
303(r) and 309 of the Communica- 
tions Act of 1934, as amended, 47 
U.S.C. 154«J, 154{j), 303(r}and309, 
and in the National Environmental 
Policy Act 42 U.S.C.A. 4321-4347. 

6. Pursuant to applicable pro- 
cedures set out in Section 1.415 of 
the Rules and Regulations, 47 CFR 
1.415, interested persons may file 
comments in this proceeding one or 
before September 29, 1972, and reply 
comments on or before October 30, 
1972. In accordance with the provi- 
sions of Section 1419 of the Rules 
and Regulations, 47 CFR 1.419, an 
original and 14 copies of all comments 
and reply comments shall be furnished 
the Commission, Comments and reply 
comments will be available for inspec- 
tion in the Commission's Broadcast 
and Dockets Reference Room. All 
relevant and timely comments and 



reply comments will be considered by 
the Commission prior to final action 
in this proceeding. In reaching its 
decision, the Commission may take 
into account other relevant informa- 
tion before it in addition to the 
specific comments invited by this 
Notice. 

Federal Communications Commission 

Ben F. Waple 
Secretary 

APPENDIX 

Part 1 of Chapter I of Title 47 of 
the Code of Federal Regulations is 
amended by adding a new Subpart I, 
to read as follows: 

Subpart I — Procedures Implement- 
ing the National Environmental Policy 
Act of 1 969. 
§ 1.1301 Basis and Purpose. 

The provisions of this subpart im- 
plement the National Environmental 
Policy Act of 1969, 42 US.C.A. 
4321-4347. 
§1.1303 Scope. 

The provisions of this subpart apply 
to all applications filed with the Com- 
mission involving the construction, 
abandonment, or razing of a structure. 
They also apply to applications for 
license for new or modified facilities 
in the Safety and Special Radio Ser- 
vices. The term "application (or appli- 
cant) for authority to construct/' as 
used in this subpart, shall encompass 
the abandonment or razing of a struc- 
ture and an application (or applicant) 
for license for new or modified facili- 
ties in the Safety and Special Radio 
Services. 

§1.1311 Notice of proposed 
construction. 

(a) An applicant for authority to 
construct is required to provide notice 
to appropriate persons or organization 
if it appears to him, or to the Commis- 
sion upon review of his application, 
that the proposed construction is like- 
ly to involve a significant environmen- 
tal problem and that notice is likely to 
provoke comment which would be 
helpful in assessing the effect of the 
proposed construction on the quality 
of the human environment. The no- 
tice shall state the nature and location 
of the construction and shall invite 
comment to the applicant on environ- 
mental considerations. 

(b) Where notice is required and 
written comment is requested, 30 
days shall be allowed for comment. 
Comments received shall be con- 
sidered by the applicant in assessing 
the effect of the proposed construc- 
tion on the quality of the human 
environment pursuant to the pro- 
visions of § §1.1313-1/1317. In nor- 
mal course, notice should be given, 
and procedures for the consideration 
of environmental effect should be 
completed, before the application is 



filed, and written comments pursuant 
to the notice should be submitted to 
the Commission with the application. 
However, the applicant may, upon a 
showing of good cause, defer notice 
until after the application is filed. In 
that event, the applicant shall state in 
his application that he is seeking 
comment on a deferred basis, and 
action on the application will be 
deferred until applicant has given .no- 
tice and complied with the provisions 
of §1.1313, §1.1315, or §1.1317, as 
appropriate. 

<c) The form of the notice and the 
persons or organizations to whom it is 
given will vary depending on the 
nature and scope of the construction 
project. The environmental effect and 
the sources of useful comment could 
be strictly local or could extend to a 
number of States. In a given case, for 
example, it could be appropriate to 
post notice at the site, to discuss the 

matter orally with neighboring proper- 
ty owners, or to raise it at a meeting 
of a community group. In another, 
newspaper or broadcast station notice 
could be appropriate. In still another, 
it could be appropriate to contact 
State or Federal environmental organi- 
zations and Government agencies 
which may reasonably be considered 
to have an interest in the environ- 
mental effect of the project. The form 
and extent of notice is left to the 
judgment of the applicant, subject to 
review by the Commission. 
§ t . 1 3 1 3 Applications entailing 
expenditures of less than $100,000. 

(a) If an application for authority 
to construct entails expenditures of 
less than $100,000, if the applicant 
has considered the matter and has 
concluded that the construction will 
have no significant environmental 
effect, and if the applicant has re- 
ceived no significant objection to the 
construction proposed in the appli- 
cation, he may, as an alternative to 
filing a preliminary or detailed en- 
vironmental report {see §1.1316 and 
1.1317), submit with his application a 
simple statement to that effect: Pro- 
vided, however, that this paragraph 
shall apply only where prior public 
notice of the filing of the application 
is given by the Commission. See 47 
US.C. 309(b). 

(b) The Commission may, upon 
review of an" application filed in ac- 
cordance with paragraph (a) of this 
section, require the submission of a 
preliminary or detailed environmental 
report, 

§ 1.1315 Applicant's preliminary 
(short form) environmental report. 

(a) Except as provided in this para- 
graph, all applicants seeking authori- 
ty for construction (and all applicants 
seeking authority to discontinue, re- 
duce, or impair service to a communi- 



JANUARY 1973 



25 



■a 



— ^^ 



ty, or part of a community, which 
involves the abandonment or razing of 
a structure owned or utilized by the 
applicant) shall fife a preliminary en- 
vironmental report. A preliminary en- 
vironmental report need not be filed 
with the following applications unless 
the applicant has been required to 
provide notice of proposed construe 
tion under § 1.1311: 

(1) Applications accompanied by 
the statement provided for in 
§1,1313 or by the detailed environ- 
mental report provided for in 

£1.1317. 

(2) Applications for authority to 

mount an antenna on an existing 
antenna tower, provided the height of 
the structure is increased by no more 
than 20 feet or by no more than 10%, 
whichever is greater. 

(3} Applications for authority to 
construct an antenna structure which 
will extend no more than 20 feet 
above ground or natural formation or 
above an existing man-made structure. 

(4) Applications proposing to lo- 
cate antenna structures within an es- 
tablished antenna farm. 

(5) Applications which involve the 
attachment of additional wire or cable 
to existing telephone poles and do not 
involve the erection of new poles, 

(6) Applications involving the in- 
stallation of additional cable in duct 
or conduit space over existing cable 
routes. 

(7) Applications for authority to 
modify existing facilities where the 
modification will involve no signifi- 
cant construction external to an ex- 
isting structure. 

(8) Applications for authority to 
construct an antenna structure which 
is to remain in place for a temporary 
period (as for the conduct of experi- 
mental operations or during the con- 
tinuance of emergency conditions) 
and then be removed, provided there 
will be no lasting effects of environ- 
mental significance. 

(91 Applications for authority to 
construct a temporary structure on an 
existing antenna site to maintain ser 
vice pending repair of the permanent 
structure. 

(10) Applications for authority to 
replace an existing antenna structure 
with a new structure on the same site 
having essentially the same height and 
design. 

(11) Applications for authority to 
construct facilities to be utilized ex- 
clusively in rendering services to the 
United States Government where the 
existence or purpose of such facilities 
is classified security information. (In 
such cases, it would appear that the 
environmental determination should 
be made by the Government agency 
for which the services are to be 
rendered under procedures compatible 



with the national security and on the 
basis of information which that 
agency alone may have.) 

(b) The purpose of the preliminary 
environmental report is to require the 
applicant, and to permit the Commis- 
sion to ascertain whether the con- 
struction proposed would involve a 
significant environmental problem. If 
the applicant concludes that the pro- 
posed construction will have a signifi- 
cant effect on the quality of the 
human environment, he should file a 
detailed, rather than a preliminary, 
environmental report* The preliminary 
report shall describe the construction 
site and the construction proposed, 
including auxilliary construction such 
as access roads and power lines. It 
may be set out as a narrative state- 
ment The following questions are 
illustrate of those which should be 
answered in the report: 

( 1 ) Harmony with man-made uses. 
How far is the proposed construction 
from the nearest structures not owned 
or utilized by the applicant? What is 
the character of these structures (e.g., 
residential, business, industrial)? How 
is the area zoned? Was it necessary for 
the applicant to obtain a zoning 
variance? State your conclusion as to 
whether the proposed construction is 
in harmony with or would disturb 
man-made uses of the surrounding 
area. If there are elements of dis- 
harmony or disturbance, state why 
they are not considered of environ- 
mental significance* 

(2) Harmony with natural uses. 
Does the proposed construction in- 
trude in any significant way upon 
wilderness areas, wild-life preserves, 
natural fly ways for birds, or like 
areas? Would construction require the 
significant destruction of vegetation 
required as food or shelter by animal 
life native to the area? If there is some 
intrusion upon natural uses, state why 
it is not considered to be environmen- 
tally significant. 

(3) Harmony with environmentally 
valuable sites. Is the proposed con- 
struction so situated as to detract in 
any significant respect from the value 
of any scenic, cultural, historic or 
recreational site? If there is some 
intrusion on such a site, state why it is 
not considered to be environmentally 
significant. 

(4) Substantial change in the 
character of land utilized. Does the 
proposed construction effect any sub- 
stantial change in the character of the 
land utilized (e.g., deforestation, 
water diversion, wetland fill, or other 
extensive change of surface features)? 
If there is some substantial change in 
the character of the land utilized, 
state the reasons for concluding that 
the change is not environmentally 
significant. 



(5) Comments and complaints. 
What efforts (if any) have been made 
to elicit comment on the environ- 
mental effect of the proposed con- 
struction? Submit copies of any writ- 
ten comments or complaints received. 
§1317 Applicant's detailed environ- 
mental report. 

A detailed environmental report 
shall be filed if it is determined by the 
applicant or by the Commission that 
the proposed construction will have a 
significant effect on the quality of the 
human environment or if there is 
reason for substantial doubt as to the 
proper conclusion. The detailed re- 
port, like the preliminary report, shall 
describe the environmental impact of 
the proposed construction and shall, 
in addition, deal with such of the 
following matters as may be per- 
tinent: 

(a) Any adverse environmental 
problems which cannot be avoided 
should the proposal be implemented. 
i 1 ) What steps have been taken or will 
be taken to reduce, minimize, or 
eliminate any adverse environmental 
impact? These could include refores 
tation, landscaping, architectural in- 
novations, sewage treatment facilities 
or arrangements, fences to limit access 
to dangerous areas. 

(2) Assuming such steps are taken, 
what significant environmental prob- 
lems remain which cannot be avoided? 

(3) Why can they not be avoided? 

(b) Alternatives to the proposed 
action. (1) What alternatives have 
been considered which could reduce, 
minimize or eliminate any adverse 
environmental impact? These could 
include relocation of the construction 
site, location of an antenna or an 
existing structure rather than on a 
new tower, self-supporting rather than 
guyed antenna towers, and so forth. 
Where receiving equipment is subject 
to control by the applicant, considera- 
tion could also be given to use of 
higher capability receivers with a 
shorter transmitting antenna tower. 

(2) What environmentally desirable 
alternatives exist that have not been 
adopted? 

(3) Why have they not been adop- 
ted? 

(c) The cumulative long-term effect 
of the proposed construction, to the 
extent it differs from the immediate 
effect of the project considered in 
isolation. 

(d) Any irreversible and irretriev- 
able commitment of resources which 
would be involved in the proposed 
construction. This provision relates to 
the depletion of limited natural re- 
sources, which is a factor we would 
not expect to be present in the con- 
struction of communications facilities! 
except possibly in limited respects 



26 



73 MAGAZINE 



(see, e.g., § 1.1315(b)(2) and (4>). 
Nevertheless, the environmental re- 
port should deaf with this factor, 
should it be present. 
§ 1 . 1 321 Commission consideration of 
environmental effect. 

(a) The Commission will consider 
the environmental effect of proposed 
construction in aJI instances in which 
a preliminary or detailed environ- 
mental report is required. 

(b) If the request is not accom- 
panied by a detailed environmental 
report, and if it is clear from the 
preliminary environmental report that 
the proposed construction will not 
have a significant effect on the quality 
of the human environment, the re- 
quest will thereafter be processed 
without further consideration of en- 
vironmental factors* 

(c) In reviewing the preliminary 
environmental report, the Commission 
may require the submission of addi- 
tional information or may direct the 
applicant to request (additional) com- 
ment and report the results to the 
Commission. Processing of the appli- 
cation will be deferred pending receipt 
of such additional information. 

(d) ff upon reviewing the prelimi- 
nary environmental report the Com- 
mission concludes that the proposed 
construction will have a significant 
effect on the quality of the human 
environment, or if there is substantial 
doubt as to the proper conclusion, the 
Commission will direct the applicant 
to submit a detailed environmental 
report and will defer processing the 
application pending receipt of such 
report. 

(e) In reviewing a detailed environ- 
mental report, the Commission may 
direct the applicant to consider addi- 
tion measures or alternatives which 
couicf reduce, minimize or eliminate 
an environmental problem and which 
were not considered in the report. The 
Commission may direct that technical 
studies be made or that expert 
opinion be obtained regarding the 
effect of the proposed construction 
and regarding the environmental, com- 
munications and cost effects of addi- 
tional measures or alternatives which 
could reduce, minimize, or eliminate 
an environmental problem. 

(f) If a detailed environmental re- 
port is submitted with the application 
or subsequently filed pursuant to 
Commission direction, the Commis- 
sion will publish in the Federal Regis- 
ter a public notice containing the 
following information: 

(1) The nature and location of the 
construction proposed. 

(2) Whether there has been opposi- 
tion to the application on the basis of 
environmental considerations. 

(3) A brief statement regarding the 
nature of any environmental problem 



dealt with in the detailed environmen- 
tal report or raised in any opposition 
to the application. 

(4) A statement that the applica- 
tion and the environmental report and 
any oppositions are available for 
inspection at the Commission and in 
the focal community or, if construc- 
tion is not localized, at other 
appropriate locations. 

(5) A statement that comments or 
petitions to deny the application on 
the basis of environmental con- 
siderations may be filed within 30 
days after publication. 

(g) Action on the application will 
be deferred for 30 days following 
publication of the notice in the 
Federal Register. Comments or peti- 
tions to deny the application on^the 
basis of environmental considerations 
shall be filed within this 30 day 
period. If a person who comments or 
petitions to deny is specially qualified 
in any way to comment on environ- 
mental considerations, a statement of 
his qualifications shall be set out in 
the petition. Comments and petitions 
to deny shall be served on the appli- 
cant The petition to deny shall con- 
tain specific allegations of fact suf- 
ficient to show that the petitioner is a 
party in interest and that grant of the 
application would be prima facie in- 
consistent with the public interest. 
Such allegations of fact shall, except 
for those of which official notice may 
be taken, be supported by affidavit of 
a person or persons with personal 
knowledge thereof. 

(h) Provisions for public notice and 
petitions to deny on the basis of 
environmental considerations shall ap- 
ply whenever a detailed environmental 
report is filed, regardless of whether 
the request would have been subject 
to notice and petition to deny pro- 
cedures on other grounds. However, 
provision, for notice and petition to 
deny on the basis of environmental 
considerations shall not open the ap- 
plication to attack on other grounds. 
Where a public notice is required for 
environmental and other reasons, a 
single notice may be published. 

(i) Where public notice is published 
in the Federal Register, copies of the 
application, the detailed environ- 
mental report, and all related 
materials will be forwarded to the 
Council on Environmental Quality, to 
other Federal agencies having 
jurisdiction of special expertise with 
respect to the environmental impact 
of the proposed construction, and to 
appropriate State and local agencies, 
with a request for comment on the 
environmental impact of the construc- 
tion proposed. The applicant may be 
required to file such number of addi- 
tional copies of the application and 
related papers as are required for this 



purpose. Thirty (30) days will be 
allowed for comment. The identity 
and qualifications of the person (s) 
who prepared the comments shall be 
specified therein. A copy of agency 
comments shall be served on the 
applicant by the commenting agency. 

(j) The applicant may respond to 
petitions to deny and agency com- 
ments within 21 days after the time 
for filing such petitions and comments 
has expired. The response shall be 
served by the applicant on persons 
who filed petitions to deny and on 
agencies which fried comments. The 
response shall contain specific allega- 
tions of fact or denials thereof, which 
shall, except for those of which offi- 
cial notice may be taken, be support- 
ed by affidavit of a person or persons 
with personal knowledge thereof. 

(k) The application, the detailed 
environmental report, and all related 
papers, including agency comments, 
shall be routinely available for public 
inspection. 

(1) The applicant shall maintain a 
copy of the application, the detailed 
environmental report and related 
papers in the local community and 
make them available for inspection 
upon request. If construction is not 
localized, these materials shall be 
made available for inspection at such 
location(s) as may be appropriate to 
provide reasonable access to persons 
affected by the proposed construc- 
tion. 

§ 1 .1323 Commission action following 
the submission of comment on envi- 
ronmental affect; detailed environ- 
mental statement 

(a) Following completion of pro- 
cedures designed to elicit information 
and comment regarding the environ- 
mental effect of the proposed con- 
struction, and upon consideration of 
all information submitted, the Com- 
mission will make a determination as 
to whether such construction will 
have a significant effect on the quality 
of the human environment. 

(b) If it is determined that the 
construction will not have a signifi- 
cant effect on the environment, the 
application will thereafter be pro- 
cessed without further consideration 
of environmental factors. 

(c) If it is determined that the 
construction will have a significant 
effect on the environment, the Com- 
mission will prepare a detailed en- 
vironmental statement. The state- 
ment will indicate the nature, loca- 
tion, and environmental impact of the 
proposed construction and will deal 
with such of the following matters as 
may be pertinent: 

(1) Measures which will or could be 
taken to reduce, minimize or elimi- 
nate any adverse environmental im- 
pact 



JANUARY 1973 



27 



(2) Alternatives to the proposed 
construction which could reduce, 
minimize or eliminate any adverse 
environmental impact, 

(3) The cumulative, long-term ef- 
fect of the proposed construction, to 
the extent it differs from the im- 
mediate effect of the project con- 
sidered in isolation. 

(4) Any irreversible and irretriev- 
able commitment of resources which 
would be involved in the proposed 
construction. 

The detailed environmental report 
may be incorporated by the Commis- 
sion into its detailed environmental 
statement. The statement, shall, in 
addition, however, take into consider- 
ation all matters of substance raised 
by persons or agencies objecting to 

the construction on the basis of en- 
vironmental considerations and shall 
contain an independent statement of 
the Commission's conclusions. 

[dj The detailed environmental 
statement will be associated with the 
application and will be routinely avail- 
able for public inspection. Copies of 
the statement will be forwarded to the 
Council on Environmental Quality 
and to individuals who filed petitions 
to deny and agencies which filed 
comments. Action will not be taken 
less than 30 days after issuance of the 
detailed statement 

(e) If on review of the detailed 



environmentaf statement the Com- 
mission finds that there is no sub- 
stantial and material question of fact 
relating to environmental considera- 
tions and that the public interest will 
be served by granting the application, 
it will grant the application. 

(f) If on review of the detailed 
environmental statement it appears 
that there is a substantial and material 
question of fact relating to environ- 
mental considerations or fhat the 
Commission is unable, on the basis of 
environmental considerations, to de- 
termine that a grant of the requested 
authorization will serve the public 
interest, convenience and necessity, it 
will designate the application for hear- 
ing on an environmental issue. 

(g) If on review of the detailed 
environmental statement the Commis- 
sion finds that there is no substantial 
and material question of fact relating 
to environmental considerations but 
that a hearing is required for other 
reasons, it will designate the applica- 
tion for hearing on non-environmental 
issues only. 

(h) Regardless of the action take, 
the Commission will issue a statement 
of the reasons for its action. 
§ 1 . 1 325 Consideration of the detailed 
environmental statement during the 
hearing and decision-making process, 

(a) If a case is designated for 
hearing on an environmental issue, the 



detailed environmental statement will 
be attached to the designation order 
and will be considered in delineating 
the scope of the environmental issue. 

(b) Copies of comments from 
Federal, State and local agencies will 
be associated with the record of the 
hearing proceeding, shall be admissible 
in evidence for the limited purpose of 
showing the views of those agencies, 
and may be used in cross-examining 
witnesses on the environmental issue. 

(c) Agencies and individuals who 
comment on environmental effect 
may be invited to participate as 
parties to the proceeding and, if not 
named as parties, may petition to 
intervene. Agencies which comment 
may be asked by Commission counsel 
or others to furnish expert witnesses 
to testify on matters of environ- 
mental impact. Subpoenas for the 
appearance of such agency experts 
will be issued, if necessary, when their 
testimony is required to lay a founda- 
tion for the admission of agency 
comments in evidence to show the 
truth of facts and the validity of 
conclusions contained thereof. 

fd) The burden of proceeding with 
the introduction of evidence on the 
environmental issue, as well as the 
burden of proof on that issue, shall be 
upon the applicant, except as other- 
wise provided in the designation 
order. 




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28 



73 MAGAZINE 




DELAY the 




REPEATER 




PETITION: To delay amendment of 
the Commission regulations (Docket 
18803) for a period of one year to 
give repeater groups sufficient time to 
meet the drastic changes which the 
new regulations demand. 

The October 17th deadline for 
amendment of the rules is whoily 
unrealistic since the new rules require 
substantia] changes for most of the 
active repeater stations now in the 
amateur services. 

It will take considerable time for 
the nearly one thousand repeater 
groups and clubs to understand the 
requirements of the new regulations, 



assess the changes that will be re- 
quired to conform to them, raise the 
money necessary to buy the equip- 
ment or parts needed for the new 
control link functions, build and test 
the new circuits and links, and get 
everything working. 

In addition to this there is the 
matter of developing the information 
needed for applying for the new re- 
peater, control and link licenses, 
which could be formidable for people 
who are working in their leisure time 
without enumeration. 

Unless the Commission delays the 
adoption of this amendment it would 



4 October 1972 

work a serious hardship on most of 
the repeater groups. 

At a recent meeting of twenty-nine 
repeater groups in Waltham the vote 
was unanimous to request the Com- 
mission to delay adoption of the new 
regulations. The entire group felt that 
the difficulties and problems posed by 
the new regulations were so severe 
that the old regulations were prefer- 
able, even though this meant the loss 
of the 147 MHz segment to Tech 
nicians. 

Wayne Green W2MDS/1 



PETITION: To amend the regulations 
for amateur repeater stations to the 
effect that control operators are re- 
sponsible for the technical operation 
of the repeater, not the content of 
emissions. The responsibility for con- 
tent would fall entirely upon the 
originating operator. 

The Commission regulations for 
controlling amateur repeater stations 
would seem to encompass two separ- 
ate functions - the technical main- 
tenance of the repeater and a censor- 
ship role over users of the repeater. 

In view of the almost total ambi- 
guity from the Supreme Court right 
on down to the lowest courts as to 
what can or cannot be broadcast or 
published, what is obscene or profane, 
etc., it is obvious that no amateur is 
properly equipped to undertake this 
function. The Commission provides 
no clear guidelines for amateurs em- 
barking on this censorhsip role. Ama- 
teurs who watch Commission licensed 
television stations and listen to Com- 
mission licensed broadcast stations 
would be hard put to make any 
reasonable decision as to what is or is 
not profane or obscene. 

Perhaps the control operator should 
follow the Supreme Court rulings and 
listen at length to transmissions made 
through the repeater to decide 
whether there is redeeming social 
merit in the matter. 

The primary responsibility for emis- 
sions would seem to rest with the 
operator originating the emissions. A 
control operator cannot shut off a 
repeater quickly enough to prevent 
some profane transmissions. Let's 



assume that the word "fuck'' is judged 
to be profane — or at least objection- 
able. It only takes a few milliseconds 
to send this word through a repeater. 
A diligent amateur with some psycho- 
logical problems (and there are some) 
can break in with a quick "fuck" 
every few minutes and present an 
insoluable problem to the control 
operator. If he is really into the 
project he can automate with a tape 
recorder and clock so he won't have 
to wear himself out rn the process. 
The short breaks make direction find- 
ing difficult. Just what is the responsi- 
bility of the control operator when 
faced with this sort of thing - and 
where does it end? 

There seems tittle reason why one 
person with problems should be able 
to effectively shut down a repeater. 
The simple change in the regu fat ions 
requested would solve this difficulty. 

It is possible that amateurs might 
feel more secure in their role of 
censor, should the Commission decide 
that this should be continued, if they 
had an official Commission list of 
words or phrases that are considered 
profane or obscene. It would make it 
much easier as the control operators 
sat there on their long nightly vigils, 
monitoring each and every trans- 
mission going through the repeater if 
they had such a list. Such a list, if 
provided, will be published and circu- 
lated to repeater control operators. 

The ability to force a repeater off 
the air with obscenities is a powerful 
weapon in the hands of an amateur 
with psychological problems. Until 
the Commission adds a psychiatric 



exam to the amateur license exam 
there will inevitably be a few people 
with serious mental problems who 
manage to get a ham license. The 
ability to learn code is no measure of 
sanity — to the contrary, according to 
some psychological circles. 

If repeaters were able to stay on the 
air it would not be difficult for 
repeater groups to locate profanity 
problems. The Commission has re- 
cently given special permission for 
repeaters to stay on during jamming 
problems to help in locating the 
offending parties. If repeater control 
operators were responsible for the 
technical operation of the repeater 
and not for censoring it, these annoy* 
ances could be dealt with forthwith. 

The Commission would consider 
that the listeners to a repeater are 
generally few in number, particularly 
in comparison to a braodcast or tele- 
vision station, and that the listeners 
are generally reasonable mature <in 
age) persons, Thus there is a smalt 
liklihood that profanity would cause 
any serious and irreperable harm. 
Since the Presidential Commission re- 
port on obscenity was unable to dis- 
cover any damaging effect from even 
the vilest pornography, the proba- 
bility that profanity on amateur radio 
would have a lasting effect is small. 

It is therefore requested that the 
Commission amend the amateur regu- 
lations to place the responsibility for 
emissions on the operator originating 
them and not on the control operator 
of a repeater which might repeat 
them* 

Wayne Green W2NSD/1 



JANUARY 1973 



29 



with Signal/Ones CX7-A 
you settled for the best 




Now meet the rest of the best 





A few short years ago, Signal/One introduced the solid-state CX7-A. It 

was quickly recognized as the world's most advanced radio transceiver. It still is. 

Now, Signal/One is more than just the CX7-A. A lot more. 

For openers, we've added two new receivers. One,'theCR-1500, a dual-channel 
system is so advanced — in selectivity, sensitivity and versatility — you won't 
find anything like it 
this side of a research 
laboratory. The 
CR-1200 receiver, our 
other new one, fea- 
tures a single VFO. If it weren't for its bigger brother, it would be the finest 
receiver you could buy. 

There's a new CT-1500 transmitter, the matching transmitter for use with the 

CR-1200 and CR-1500 receivers. It incorporates 

all modes of operation and includes the famous 

Signal/One RF envelope clipping, broadband 

tuning, full-automatic CW keying, and many 

other features. 

We're also introducing a new transceiver, the CX-10, which contains several 
CX7-A features. In addition, it can be used with either our new AC or DC power 
supplies, an external VFO, and other accessories. 

Our new accessories include a deluxe station 
console, speakers, 2-meter and 6-meter 
transverters with direct digital readout and FM 
capability, and custom microphones. 

In the past years, there were one or two names in amateur radio gear that 
meant the finest. In their time they were. 

Times have changed. Now, if you want the finest, choosing is easy. 
It's all at Signal/One. 



13130 Yukon. Hawthorne, Ca. 90250 (213) 679-9022 






Loring C. White WIODI 
26 Boswell Road 
Reading MA 01867 



HANDIE-TALKIE 
TOUCH 



TONE 



Make phone calls through the local 
repealer while walking down the street 
with this modified HT-220. 

or those of you who might like to 

make phone calls from your back yard 

or who would like to make up a "phone in 

the shoe" system a la the 'Get Smart" TV 

program, here is a way to do it I 

If you happen to find a Motorola HT-220 
2 meter handle talkie (which, incidentally, is 
smaller than my shoe size) in the shack 
junkbox, you are a long way to realizing 
your own wireless touch tone system. You 
will need the following additional items: 

1. Touch pad Chomerics #EF-20071, $7-95 

2. Tone generator - hybrid chip — Micro- 
systems International Canada #ME-8900 
CA., $25.00 

3. 5 juF capacitor 

4. 700^ resistor 

5. 40 KQ resistor 

6. 10,00011 micro potentiometer 

7. Plexiglas shim plate 3 x 2.25 x 1/8 in. 
Looking at the photo you will see that 

the "pad" is mounted just below the speaker j 

grill. It is necessary to insert the plexiglas I 

shim plate between the HT-220 case and the 

pad in order to take up space from the 

connecting pins on the back of the pad. So 

that the pad and spacer will lie flat against 

the front cover, it will be necessary to file 

the rounded surface of the cover flat, just 





under the pad. The file work is about the 
toughest part of the whole job, but is very 
important to prevent warping of the thin 
pad, 



JANUARY 1973 



31 





1 


2 


1 3 


^ ' 






4 


5 


6 




7 


8 


9 








* 





# 





FRONT 





























A 






" 


R - 




(Tl 






M 


F 




• 

• 






i* — 












« 













REAR 

Fig m 1 . Front and rear view of the touch pad and its 
connections* 

It will he necessary to drill two small slots 
through the HT-220 front to accommodate 
the eight miniature pins on the back of the 
pad- Remove and disconnect the HT-220 
front cover and carefully locate the two pin 
areas free of the internal battery connecting 
strips. The pad may be conveniently at- 
tached to the cover using contact cement- It 
may be advisable to hook up the pad first to 
determine if everything is operating okay. 

The hybrid chip may be counted just 
above the lfc PL Tone" compartment in the 
"thick case* model and the additional com- 



5UF 




TONE 



. G£NERATOR 
5 12 



FREQUENCY 
SELECTING 

CONTACTS 




oMIKE 
HT-220 



12,5 TO 
38 V 



portents cemented to the chip case, between 
the pins. 

Keeping the wires as short as possible, 
interconnect the pad and chip as follows: 



Chip Pm 
4 

5 
6 
8 
9 
10 

11 
12 
13 
16 



L2,3, 14,15 
I found 



Fig, 2, Schematic showing connections between 
touch pad and tone generator. 



Pad Pin 

A 

B 
C 
H 
G 

F 
E 
D 

Neg, 1 5 V battery 
Through 7G0£2 to 
pos. 15V battery 
N.C. 
that some rf problems disap- 
peared after bypassing a few of the chip 
contacts with .001 juF ceramic capacitors to 
the negative battery terminal- 

The degree of bypassing required will be 
determined by the application, antenna 
matching, etc. 

Be sure to take the positive battery 
connection from a point on the HT-220 
transmitter board so that the pad will be 
"on" only during transmitting periods. 

The system is quite compatible with the 
Bell Tone System even though the output 
tones are considered to be pure sine wave as 
compared to the tones coming from the 
regular Western Electric pads, 

Adjustment of the tone output level is 
most conveniently done by observing the 
transmitter output on an oscilloscope. 

Adjust the 10,0000 potentiometer for 
proper FM deviation level in accordance 
with the autopatch requirements of your 
favorite repeater. 

We have made several phone calls with 
the handie-talkie touch tone system over the 
Weston repeater, WA1KHB, and fired up the 
"Sanford link" through K1MNS from a 
location 15 miles north of Boston, 
Massachusetts. 

A completely assembled 12-button pad 

with tone generator and all parts is available 

for $30.80 from Tom McKeever Wl WJR, 28 

Leigh Road, Norwell MA 02061, He also has 
quantities of 16-button pads for $35,12. 

Please add $1,20 for postage and handling. 

...WIODI 



32 



73 MAGAZINE 



HOW TO 

WIN 



Chet Latawiec VE3CFK 
569 Carlton Street 
St. Catharines, Ontario 




THE 
PILEUPS 







There is an XT2 sitting on the band 
and everybody you can think of is 
calling him, trying to beat the other fellow 
out. So you get in and try your luck with 
your kilowatt and your dipole. If you're 
lucky, you might work him — that is, if 
you live a couple of miles away from the 
chap. If not, there is no conceivable way 
you can work the fellow within the next 
couple of hours. 

So get away from the ordinary and build 
yourself a three-element, wide-spaced beam 
and be the first to work that rare DX. I 
guarantee that with this type of antenna 
you can beat out any three-element triband 
beam and even some of the short-boom 
four-element beams. 



This three-element, widespaced beam is 
plenty sturdy; it is of all-aluminum con- 
struction and so far has withstood winds 
up to 80 mph and a few Canadian ice 
storms. 

If you intend to build this beam, do not 
alter any of the physical dimensions, as this 
will decrease the efficiency of the antenna. 
The frequency of the array was set in the 
middle of the band to allow its use on the 
CW and phone portions of 20m. 

The elements are constructed of thin- 
wall aluminum tubing, of the diameter and 
length stated in Table L 

Each element is constructed of seven 
pieces. The center portion is 1 in, inside- 



JANUARY 1973 



33 







The view of the antenna element and its 
mounting. 

diameter aluminum conduit to give strength 
to the remaining portions of the elements. 
The conduit is slotted at each end on both 
sides for about 3 in- 

The remaining portions are fitted to- 
gether to the values shown in Table II. 
About 4 in, from each individual piece of 
tubing is placed a self-tapping screw to 
insure that the elements do not move or 
rattle. At the end of each element is placed a 
drip hole about 1 in. from the end and a 
cork is press-fit in the end of the tubing to 
prevent the elements from whistling in the 
wind* 

All three elements are constructed in the 
same manner, the only difference being 
their physical lengths. To obtain the proper 
length on each side of the center of the 
boom, the thin-wall aluminum portions of 
the elements are adjusted in or out of the 
aluminum conduit. Once the proper dis- 
tance has been attained, drill a hole about 
8 in. from the edge of the conduit and 
drop a self-tapping screw in, and also place 
a hose clamp about 1 in. from the end of 
the conduit* 

Just a small note here on cutting the 
thin-wall aluminum. Most of the tubing 
comes in 12 ft lengths, so on the antenna 
portion cut the tubing in half and to obtain 
the proper lengths for the director and 
reflector for their overlap cut the tubing 6 
in. off center, 

The boom is a 1X7 ft 4 in, piece of 3 in. 
aluminum irrigation tubing. It is the most 
expensive single portion of the antenna, 
but is well worth the money spent, from at 



least the standpoints of the strength it gives 
and its light weight. 

At each end of the boom there is a 
circular block of wood, the diameter of the 
pipe, which is fitted in the end of the pipe 
and then nailed. This precaution is neces- 
sary unless you are a bird lover. 

The main feature of this antenna is the 
method used to mount the elements to the 
boom and keep them there. Aluminum 
plates (0,25 in. thick) are used in this deal. 
The plate is held to the boom by two 3 in. 
muffler clamps. The plate in turn holds the 
element with two smaller muffler clamps as 
shown in Fig. 2. The plate is first mounted 




ELEMENT LENGTHS 

REFLECTOR 35 ft-5 in. 
DRIVEN EL. 33 ft -5 in, 
DIRECTOR 3t ft -5 in, 



ALL MOUNTING PLATES 
ARE 8 in. i 8 m. SQUARE 



ELEMENT 
SECTION 


ELEMENT 


TU8ING 
DIAMETER 


DIRECTOR 


DRIVEN EL. 


REFLECTOR 


A 


2 ft 


2 ft 


2 ft 


3/4 to r QDl 


a 


5-1/2 ft 


6 ft 


6-1/2 ft 


7/8 in, O.D. 


c 


5-1/2 ft 


6 ft 


6-1/2 ft 


1 In. 0.0, 


D 


10 ft AL CON 


10 ft AL, CON. 


10 ft AL. CON. 

1 


1 in. L0L 



TABLE I -THIN WALL LENGTHS 



ELEMENT 
SECTION 


DIRECTOR 


DRIVEN EL, 


REFLECTOR 


A 


1 ft- 3 in. 


1 ft- 3 in. 


1 ft- 3 In. 


B 


4 ft~9 in. 


3 ft- 3 in. 


5 ft- 9 in. 

- 


C 


4 ft- 9 in. 


5 ft- 3 in. 


fl ft-9 in. 


D 


10 ft 


10 ft 


10 ft 



TABLE 2 

THE W.UES GIVEN ARE FROM THE EDGE OF ONE PIECE TO THE 
EDGE ^ i HE OTHER. 



34 



73 MAGAZINE 



SUPPORT STRUTS 



DIRECTOR 




CLAMP 
3 in SUT 



COA* FEEDLfNE 



TUBING 



REFLECTOR 



SEE DETAIL A 



Fig. 2. This sketch shows the construction 
of the center plate of the beam and also 
the position of the gamma match. The 
diagram should be self-explanatory* 

on the boom with the 3 in. clamps and 
tightened slightly. It should be mentioned 
that all hardware used was galvanized 
heavily and then lead plate was used on all 
the nuts and bolts to prevent seizing and 
rusting. 

The aluminum conduit portion of the 
elements is mounted and tightened on each 
plate. There are two pieces of grappling 
iron, about 6 in- long, which are placed on 
each side of the boom, one each under the 
nuts which are the furthest away from the 
ends of the boom. Make sure that the 
distance from the center of one parasitic 
element to the other is 26 ft 8 in. 

The center plate is a two-fold job. Two 
pieces of 2 x 4 are cut to length of the 
plate and long bolts about 7 in. are placed 
through the plate and boards and slightly 
tightened. 

This plate is mounted to the boom as 
the other two were, using muffler clamps 
again. Then the conduit is mounted and 




OUTER 
COVERING 



BRAID 



•i. ii 



DETAIL A' 

clamped in its place. By sighting at the end 
of the boom, look at the three pieces of 
conduit and make sure that alt three are 
parallel to each other, then tighten all the 
muffler clamps. 

Now the remaining portions of the 
elements are placed in their respective 
places and finally the hose clamps are 
installed and tightened. When you do this 
make sure that the drain holes are on the 
bottom facing the ground. 

Matching 

On this particular antenna, a gamma 
match was tried and when adjusted pro- 
perly, proved to be a very wise choice 
because the swr was flat across the band 
and did not exceed 1.2: 1. Ft was con- 



JANUARY 1973 



35 




* * 



The view of the end element and its 
mounting. 

structed out of a TV antenna element. The 
shorting b;ir was constructed from alumi- 
num and was made so that the center of 
the aluminum conduit to the center of the 
48 in, piece of TV element was 6 in. This is 
very important. The capacitor was made 
out of a length of RG-8, 41 in, of the outer 
covering was taken off and then 40 in. of 
the copper shield had the same treatment. 
On the remaining I in. of braid, there was 
soldered a brass or copper bracket which 
will later be used to mount it to the beam. 
The remaining portion of the stripped end 
of the coax was placed inside of the gamma 
tubing, 

The bracket must be mounted onto the 
boom and it must keep the 6 in. from 
center to center constant. 

The bracket is held in place by two 
self-tapping screws placed on either side of 
the hump in the bracket. At the other end 
of the coax a coaxial connector was placed 
to provide easy connection to the feedline. 
The inside of the shorting bar is 44 in. 
from the center of the boom. 

Installation 

The beam is installed on the mast by 
means of another plate. This plate is made 



of Va in, steel and is drilled to accommo- 
date the four [ong holts which arc on Hie 
center plate of the beam, This plate- is 
welded onto the mast to provide for a good 
slip-free connection. 

The antenna is lifted onto the steel plate 
and the bolts placed in the hole, The nut 
and lockwashers are placed nn it and all 
mounting hardware is tightened. 

Adjustment 

There need not be any adjustments 
necessary to the elements if precautions 
were taken in acquiring the proper sized 
tubing and the measurements followed to 
the inch. 

There may be, however s nie adjust- 
ment needed on the gamma match. The 
values that were given in the above e 
used on three previous antennas identical 
to this one and no adjustment was net 1. 
However, should the need arise that it d<>< 
need attention, then the bracket on the 
gamma match must be taken off and the 
end of the coax trimmed, about half to a 
whole inch until the swr is down (o at least 
1.5:1. 

Performance 

With a beam like this you should not 
have any trouble working that XT2. You 
could even work 200 countries with a 
100W, thus eliminating the need for a big 

kilowatt. This beam can outperform any 
antenna in its class. 



Specifications 

Gain 
FBR 

Side Att 

Boom 

Turning Radius 

Weight 

Cost 



8.5 dB over a dipole 

25-30 dB 

50 dB 

27 ft 4 in. x 3 in. 

22.5 ft 

45 lb 

$80 



Acknowledgements 

Thanks goes to Howard Cowling 
(VE3WT), whose plans and ideas were 

presented in this article and also for the 
help he gave me in epai d p. nt- 

ing it. T hanks also goes to B^rny Gold- 
chuck (VE3FYG), who took the picl 

VL FK 



36 



73 MAGAZINE 




THE 



Ed Gribi WB5IZF/YB8AAP 
Holland Park £M 
Singapore 10 




• • • 




OF THE GIAN 
THE 

ESTABLISHMENT 



A phenomenon of the last five years in 
_the amateur market has been the 
emergency of Japanese manufactured rigs of 
high quality, innovative design, and highly 
competitive pricing. The leader of this pack 
has been the Yaesu Musen Co., Ltd.* which 
probably sells more HF SSB transceivers 
than all the rest of the world manufacturers 
put together. Certainly then a visit to the lair 
of this giant would be a highlight for a ham 
visiting Japan. This is a record of my too 
brief visit with some tips for those of you 
who have the opportunity to pass through 
Tokyo in the future. 

After concluding my busines in Tokyo, 
we had a free afternoon before plane time. A 
call indicated the Yaesu plant, somewhere 
out in the wilds of south Tokyo, would be 
happy to see us. Another phone call to the 
plant by a most helpful lady at our hotel 
information desk elicited the information 
that the plant was about a 40-minute taxi 
ride, and generally in the direction of the 
airport , but finding the place was a little 
difficult even for Tokyo. For five solid 
minutes she took down instructions in 
Japanese characters and then copied them 
neatly for the taxi driver — a must for even 
the simplest jaunt in this world's largest 
metropolis. 

We piled into a taxi selected for us by the 
doorman, and the driver placed the precious 
sheet of instructions for quick reference. We 
shot off on one of the expressways, ran it to 
its end, then continued for miles on surface 
streets, finally narrowing down into some 
lanes. The highlight of this little journey for 
me was the many tantalizing glimpses into 



the gardens of private homes, each different 
but immaculate in design and appearance in 
the Japanese fashion. Thirty-five minutes or 
so brought us into the area where the driver 
started looking at me questioningly as I 
shrugged my shoulders. A couple of circles 
and obviously conflicting directions from 
people on the street suggested we were not 
making headway. At a phone booth, 1 put 
the driver on the phone to the plant for 
further orientation. Soon we had a 3 
element yagi in sight and after one more 
circle we arrived at an unassuming three- 
story building. 

Mr. Shigeru Takagi, KH3NUD, Sales 
Manager, met us and said this was really not 
now a manufacturing plant but rather the 
final inspection facility. One factory is west 
of Tokyo and the main manufacturing faci- 
lity is north of Tokyo, in Fukushima. Three 
assembly lines are in operation at that plant 
and a new plant is under construction. 
Shigeru told me that there were forty 
FT-lOTs being turned out every day and 
almost forty of the FT-40 1/560-570 series. 
Add to this the several linears, the FT-200's 
(very popular in Japan), and the growing 
two meter line — Yaesu must have the lion's 
share of the amateur market. Their own 
estimate, admittedly not exact, is 80% out- 
side the U.S. and perhaps 20-25% in the 
U.S. 

Time was short, so up the stain we went 
to meet Kim, JA1KRZ, in charge of the 
inspection facility. In a room about 40 x 
100 feet about 25 technicians worked, each 
at an individual well-equiped test bench. 
Along one wall, literally stacked like hot 



JANUARY 1973 



37 




Just look at all those transceivers getting a final checkout before packaging. Recognize yours? (Photo 
courtesy YAESU) 



cakes (which I guess they are selling like), 
were rows of the FT-2B and FT-2 Auto 2 
meter transceivers. Kim showed us how the 
auto-scan feature worked on the FT-2. It 
was fascinating to watch the blinking red 
lights scan for an active channel. It was 
surprising how much 2 meter action existed, 
particularly when I learned that this was ail 
direct. Repeaters are not yet legal in Japan, 
but the VHF boys are hoping this will be 
changed. That should be a boom to watch - 
can you imagine a country with a growing 
amateur population nearly that of the U.S., 
complete with a large, enthusiastic VHF 
contingent, suddenly being allowed to es- 
tablish repeaters? The mind boggles. 

The 2 meter gear intrigued us but it was 
equally impressive to see all the HF gear 
being given final testing and alignment. I 
noticed, by the way, that most of the test 
benches included Yaesu's own frequency 
counter. Shigeru told us that there were at 
least 100 hams employed by Yaesu. Yaesu 
must be the largest single employer of radio 
amateurs in the world. 

All too soon lights were starting to go out 
and people were starting to head for home 
Time for us to bid our "Sayonara" and 
depart. But, for the rest of you , here are 



some tips if you should have an opportunity 
to go to Japan, i might add many of the 
things I did not do, myself. If you know 
your plans ahead of time, by all means write 
ahead and let them know your itinerary and 
interests. Letters will reach Yaesu Musen 
Co., Ltd., at Central Post Office Box 1500, 
Tokyo. I would imagine that a letter to the 
JARL, Box 377, would produce some in- 
teresting results. Yaesu's main office is at 3 , 
3-Chome, Yaesu, Chuoh-Ku, Tokyo, Phones 
271-771 1 to 7716. The factory we visited is 
at 2-15, 1 Chome, Kugahara, Ota-Ku, 
Tokyo, Phones 753-6141 to 6145. 

Another place worth a visit in Tokyo is 
the Akihabara district of Tokyo where 
hundreds of eleectronics supply stores are 
scattered over 5 or 6 square blocks. Four or 
five of these stores deal specifically in ham 
gear. But, regardless of where you go in 
Tokyo, the rule is to have the hotel write the 
address and instructions in Japanese and 
have the doorman make sure the taxi driver 
understands them. 

In any event, you'll find that the innate 
politeness and hospitality of the Japanese 
will make your explorations delightful ex- 
periences. Sayonara. 

.. .WB6IZF 



38 



73 MAGAZINE 



Tom Johnson KL7GGB/4 
3001 Roxbury Road 
Birmingham, AL 35209 



ANOTHER 

INTEGRATED CIRCUIT 

FREQU 
COUN 





This counter was constructed as a per- 
sonal project to help me better under- 
stand the workings of integrated circuits and 
their operation. That's why I used RTLs 
together with TTLs. I also had them on hand 
so it was cheaper than buying new ones. All 



of the circuits used are standard with no 
exotic tuning or adjustments. 

The only test equipment required is a 
VOM to check voltages and a scope to 
troubleshoot possible bad connections. To 
set the time base generator on frequency I 




The 50 MHz frequency counter. Notice how the author included a metric rule in the photograph to in- 
dicate the unit's width of 30 A 8 cm. 



39 




* ♦ 3 6v 



O LOOK Hi OUT 



« GROUND 



Fig. J. Time base generator. 



recommend comparison with a commercial 
counter or comparison with WWV using a 
scope to get as close as possible to the exact 
frequency. The common practice of zero 
beating by ear is just not accurate enough. 
This is especially true if you want the 
counter to have the best possible accuracy 
that this design will give. I calibrated a ten 
MHz crystal to WWV, then adjusted my 
counter to read 10.000.00+, That was the 
best method available with my limited re- 
sources. 

Construction Ideas 

The arrangement of the decade counting 
units (DCU) is straight in line with the 
SN74196 being first on the right as viewed 
from the front. The rest of the ICs were 
placed so as to keep the wiring as short as 
possible to minimize interference between 
sections. The main part of the counter was 
constructed on a 4 x 6" vector board with 
.1" center spaced holes which match the 
spacing of the ICs. No sockets were used 
although all ICs are removable. This was 
accomplished by using integrated circuit 
terminals. These terminals come in strips of 
56 each. This is a convenient size as the 
whole strip can be inserted in the holes, 
wired and then the top of the strip is broken 
off giving the equivalent of sockets with less 
cost and effort. In my counter I use seven 
display tubes which fit well on the board 
and came out just right for the integrated 
circuit terminals. I use AKZ type tubes and 
sockets, they also fit the .1" spacing on the 



vector board. An etched circuit board would 
improve the looks, but that would not allow 
much flexibility in the development of the 
counter. 

Input Amplifier 

In the construction of the input amplifier 
I tried several types of integrated circuits 
before settling on the SN72733. Four 
2N2369's were tried first and found to be 
unsatisfactory. The RCA CA3018 was then 
tried and found to be an excellent input 
when used with a 74H10 input gate, it will 
go up to 32 MHz with no problem. The 
SN72733 from Texas Instruments will work 
up to 50 MHz with the SN74S10 input gate. 
You have to use the combinations together, 
the SN72733 with the 74S10 for 50 MHz, 
the CA3018 with the SN74H10 for up to 32 
MHz. 

If you want lower frequency operation 
you can use the CA3018 with a SN7410 and 
by this route be able to use a SN7490 for 




o NC 



Fig. 2, Input amplifier circuit. Pins 3, 4 t ll r 12, are 
open. Pins 2, 6, 9, 13 NC, 



40 



73 MAGAZINE 



T T7 

7 G 7 




TO 74HI0 



-O STROBE TO 7475 S 



o RESET T0 7490S 



J 

Fig. 3. Timing circuit. 



the first DCU. This combination would be 
able to count to approximately 20 MHz, I 
wanted to go all out and count as high as 
possible, so I continued until I could get at 
least 50 MHz, This is the only section of the 
counter where different designs were tried. 
The rest of the counter was designed and 
constructed with very few changes being 
made. From the input gate the signal is fed 
into the first DCU. All of the DCtTs are 
alike except the first one which uses a 
SN74196, SN7475 and SN7441 which gives 
the first digit. The rest of the DClTs are 
SN7490, SN7475 and SN7441. The 
SN74196 is used in the first DCU because it 
has a higher toggle rate (50 MHz) than the 
SN7490 which will only go to 20 MHz 
maximum. The SN74196 has to be reset 
through an inverter because it needs a 
negative going pulse to reset whereas the 
SN7490 needs a positive going pulse. 

The input gate is opened and closed by 
the Q output from the JK flip-flop SN7473. 
The Q output is connected to the four wide 
two-input nand gate SN7400 together with 
pulses from decade scaler number four to 
generate the strobe and reset. The diodes are 
used to decouple the set up pulses passing 
current in one direction only. The SN7400 is 
blocked from producing the strobe and reset 
except when the gate is closed by the Q 
output from the JK flip-flop. When the 
strobe is generated the count is transferred 
to the read out, then the reset is generated 



resetting the DCU's and scalers five and six 
to be ready for the next sequence in 
counting. This is a good scheme and gives a 
good ratio of read out time to count time. 

Time Base Oscillator 

The time base oscillator uses a 1 .4 MHz 
crystal in a circuit using a 2N706. The 
padder in series with the crystal allows 
calibration to the exact frequency. The 
buffer is also a 2N706 that serves to drive 
the first juL 923 in the divide by seven 
circuit. Pin 5 of the third juL 923 is 
connected to another 2N706 in a half mono- 
stable circuit resetting the first juL 923 
forcing a divide by seven. The last jlzL 923 
divides by two giving 100 kHz output. This 
can be modified to fit any crystal as long as 




Top view of the counter. Note the shielded 
compartment that separates the input circuitry 
from the rest of the unit. 



JANUARY 1973 



41 




Close up of the main circuit board showing the IC layout and Nixie tube mounting. 



it can be divided by a whole number. The 
whole divider chain can be eliminated if you 
have a 100 kHz crystal. The 100 kHz from 
the RTLs is run through one section of the 
SN74H10 to improve the wave shape, that 
gate was left over from the input IC, so no 
parts were added. From the SN74H10 the 
100 kHz is fed into the first of six decade 
scalers SN7490. Connected to the first three 
decade scalers is a four wide two input 
andor-invert gate SN7454 together with 
four sections of hex inverter SN7407 making 
it possible to select one of four frequencies: 



TO 

<r 

DCU 
CARRY 



3UT 


5 
< 

in? 


V 

> 

5 






< 


5 






1 


* 


TO 

PtHS 
ON 

NIXIE 
TUBES 

- .* 


\4 


SN7490 


(5112 


2 


SN7475 


16 


3 


SN744I 




cei 


Jeg] 

M 


\ 
3 


19 


4 


a , 


* ; 


4 


13 it 






Lf21 
9 


6 


10 


6 


'4 




1 3 

" c 


3 


ID 


2 


(9) 

i 


7 


t 


7 


7 


KM 

2 




11*} 


121 


4 

■3 






' & 




:set 


m 

1 


10 






< 


12 
J 






( 


12 

i 





STROBE 



Fig. 4. The SN74196 requires an inverter on the 
reset. Pin numbers in bracket are for the SN741 96. 
Pins 1, 3, 4 f 10, 11 are open. Pin 7 Gnd, 14 +5V. 



100 kHz, 10 kHz, 1 kHz and 100 Hz. These 
four frequencies, after going through the last 
three decade scalers, will give integration 
times of 0.01, 0.1 , L0 and 10 seconds. The 
0.01 second integration time has no real 
value in this design and need not be wired. 
However, if you use less than seven read 
outs, you will need it to read tens of MHz, it 
is also useful in checking and trouble- 
shooting. 



**5V 



<f TTL 




CjROUNO 



Fig. 5. Input amplifier for low level signals, 20 }JiV 
to 4mV3db 800 Hz to 32 MHz. 



42 



73 MAGAZINE 



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VHF 



ENGINEERING 



W2EDN 



1017 CHENANGO ST. BINGHAMTON NY 13901 



Power Supply 

The power supply uses a transformer 
rated at 500 Vet 50 mA and 63 V 1.2 A. 
Using a full wave rectifier on the 500 volts 
and 40 jlxF 450 volt capacitor gives approxi- 
mately 300 volts dc under load. Three 
27,000£2 two watt resistors in parallel drops 
the voltage down to the zener diode rated a I 
180 volts 10 watts. In series with each Nixie 
tube, there is a 22 ? O00£2 half watt five 
percent resistor. The recommended voltage 
for the Nixie tube is 140 volts at approxi- 
mately 2Vz mA. This arrangement can be 
changed to fit what you have on hand by 
changing the series resistor to a value that 
will assure that no more than 140 volts are 
on the Nixies. The low voltage supply is a 
full wave bridge rectifier with 40,000 juF 
filter capacitor which gives about 8 volts. 
This is regulated by an FC, LM-390-K, that 
has a rated output of 5 volts at 1 ampere. 
The counter draws a little over half of that 
and runs cold. This regulator is cheaper than 
building one from scratch and is really better 
than the ones I have been able to make. The 
power supply is built right in the I 2 x 8 x 3" 
chassis adhering only to an arrangement that 
saved as much space as possible. Not shown 
on the schematic is a minus five volt power 
supply for the SN72733 which is necessary 
if you decide to use this system. I managed 
to crowd in a small filament transformer 
with a half wave rectifier, 100 juF capacitor 
and a five volt zener diode. The SN72733 
draws less than 30 mA, so not much is 
required- If you use the CA3018 this is not 
necessary. If you want to measure frequen- 



INPUT 
FROM 
CA 3Gte 




SN74I96 



GATING FROM 
SN7473 



lOOKHi FROM 
RTL CLOCK 



TO FIRST DECADE SCALER 
PIN 14 SN74 90 



Fig. 6. Input gate using a SN 74H10 

cies less than 10 MHz only, you could build 
a transistor amplifier using almost any fast 
switching type. In that case three or four 
read outs would be satisfactory. Then there 
would be no need for the different integra- 
tion times so the SN7454 together with the 
switch could be left out. If you really want 
to cut it down you could use the power line 
frequency for the rime base dividing by six 
to get .1 second integration, throw in a 
SN7490 to get one second- I see no reason 
why this scheme would not work although I 
haven't tried it myself. 

Trouble Shooting 

Trouble shopting of integrated circuits 
requires a lot of pre-planning. Following are 
some of the things I have learned by working 
with integrated circuits. First, with a piece 
of hookup wire, jump pin five of the last f±L 
923 to the input, You should get 100 kHz 



=d 



sw 



H7VAC 



^L 



IA 



X 



Ol 



Of 



T R ANS FOR ME ft R AT E D AT 
SOOV CT 50 MA 
65V I2A 



f 



PLUG IN 
REPLACEMENT 
FOR 6X 4 



X 



^ 4D^F 
_L 450V 




50P1V 
5A 



y ^v PILOT 
(^ LAMP 




-O MBOV 



iftOV 

JOW 

ZENER 



LM390K 
5V 
I A 



40O00j*F 
7V 




5V 



o S6V 



Fig. 7. Schematic of the regulated power supply. 



44 



73 MAGAZINE 




Rear of the counter showing the time base 
oscillator circuit board and the three 27 K power 
supply resistors mounted behind the filter 
capacitor. 

on all ranges. Do not confuse this as an 
indication of the accuracy of the counter 
but as an indication that all systems are 
working- With a scope on pin 8 of the 
SN7454 you should get 100 kHz with the 
switch in the .01 second position, 10 kHz in 
the .1 second position, 1000 Hz in the one 
second position and 100 Hz in the ten 
second position. To check the rest of the 
decade scalers, put the switch in the .01 
second position and follow the signal 
through the SN7490 , s by checking the pin 
1 I of each one, scaling down by a factor of 
ten for each IC. Finally, on pin 12 of the 
SN7473, check for the gate opening and 
closing, and on pin 1 3, for the timing pulses 
to the SN7400. Set the switch to the ten 
second position and measure the gate open- 
ing and closing with a VOM. The up's and 
down's occur pretty fast but it will show on 
the VOM. Pins 8, 1 and 1 2 of decade scaler 4 
should be nice square waves with the fre- 
quency measured depending on the switch 
position. Pins 1 and 2 of the SN7404, pins 2 
and 1 2 of SN7400 should ail be square 
waves, however, the strobe and reset pulses 
are hard to lock on even with a triggered 
scope due to long down to up time. 

Using your VOM, momentarily jump pins 
3, 4, and 5 of SN7400 to ground and read a 
high on the reset line. Do the same thing on 
pins 9, 10, and 1 1 ; measure a high on the 
strobe line. Do not forget the reset on the 
SN74I96 is inverted by one section of the 
hex inverter. An indication that all is not 
right is that one of the read outs has a 
preference for one digit. This can be caused 



by a bad connection from the SN74 l >0 to 
the SN7475 or from the SN7475 to the 
SN744L A bad connection from the 
SN7441 to the Nixie tube will show up as no 
digit on some count and a short will show 
one digit all the time. Trouble in the strobe 
line will cause it not to transfer or will 
flutter during counting. Trouble in the reset 
line can be detected by a continuous digit on 
the read out after the input has been 
removed and sufficient time has passed to 
reset. Be certain the connections between 
the SN7490, SN7475 and the SN7441 are 
correctly wired. An error in this department 
will cause the SN7441 to decode wrong. 
This could show up the same as a bad 
connection; that is, with no input and after 
the reset there would be some number on 
the read out. Depending on the cross and 
how it was decoded would determine what 
number would be on the read out. 

The best bet is to be certain they are 
correctly wired the first time. If you think I 
was wrong the first time, you're right. 

With a grid dip oscillator couple some rf 
into the counter using about twenty turns of 
hook up wire around the GDO coil. Starting 
at the low end of the dial, 1 .6 MHz on mine, 
slowly increase the frequency until you get 
up as high as you can, adjusting the wire 
positioned on the coil to get the best 
coupling to the counter, Don't be dis- 
couraged by dead spots or a frequency 
difference between the GDO and the count- 
er. The hook up wire will load the GDO 
down and make the dial read high. Using a 
tube type Millen GDO I had no trouble 
getting the counter to work to 50 MHz, after 
that I had a hard time getting in enough rf to 
count. I believe this system design would go 
up much higher in frequency, perhaps up to 
two meters. 

. . .KL7GGB/4 

References 

WA2IKL, "A Digital Readout for Your VFO," 73, 
August 1971. 

Integrated Circuit Catalog CC-401, Texas Instru- 
ments. 

Digital Electronics for Scientists, Mais tad t and 
linke. The Heath Company, 

RTL Cook Book, Donald li. Lancaster, Howard W. 
Sams Co, 



JANUARY 1973 



45 



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3915 Pleasant Ridge Road 
Boulder CO 



AN I MPROVED 
AUDIO SPEECH 

PROCESSOR 

Increase the effectiveness of your SSB signal with a unit that compresses, 
clips and filters your audio before it modulates your transmitter. 



T\ he advantages of speech processing for 
single sideband voice transmitters have 
been pointed out from time to time for a 
number of years. Speech compression pro- 
duces some gain in voice power and may 
reduce peaks substantially if the attack time 
is fast enough. It offers another advantage of 
keeping the speaker's voice level constant as 
his speech power varies or as he moves his 
head. Clipping increases the relative power 
of intelligible speech by cutting off voice 
peaks. Since truncated waveforms produce 
high-order harmonics whose presence is en- 
hanced in the single sideband mode as 
compared to AM, it is especially important 
that clipping be followed by bandwidth- 
restrictive filters. 

Figure 1 is presented to demonstrate the 
advantages of peak reduction. Figure la is a 
simplified presentation of a portion of a 
typical voltage waveform of a syllable, as 
displayed on an oscilloscope with an inter- 
nally triggered sweep. The spikes contribute 
almost no intelligence, yet ah rf amplifier 
must not be driven beyond where the spikes 
flat-top; i.e., saturate the final stage. Most of 
the intelligence is in the small wiggles. By 
clipping the spikes and amplifying the useful 
portions of the waveform to drive the final 
up to flat-topping, the net intelligible voice 
power is increased. 

The rf envelope of unprocessed speech 
may look something like Fig. lb. The width 
of the spikes increases in a manner suggest- 
ing a train of pulses passing through a circuit 
of restricted bandwidth. The small wiggles 



are a mixture of intelligible speech and 
higher harmonics of the repetition rate of 
the spikes. When peaks are reduced by 
processing, the waves representing intel- 
ligible speech produce rf envelopes which are 




I A) 

MICROPHONE 
OUTPUT 




(8) 
SSB 

TRANSMITTER 
OUTPUT RF 
ENVELOPE 



Fig. 1. Unprocessed speech: simplified picture of 
part of a spoken syllable seen on a triggered sweep. 



not exceeded in height by any spikes. In 
fact, it is difficult to trigger the oscilloscope 
internally under these conditions because 
there is no longer a predominant group of 
spikes. 

The speech processor to be described 



JANUARY 1973 



47 



■■ 



resulted from an attempt to reproduce the 
solid state processor of WB2EYZ (see Re- 
ference 1), substituting NPN silicon transis- 
tors for the PNP germanium types. It was 
noted in the author's experiment that any 
appreciable amount of ALC feedback would 
cause the unit to multivibrate. Even if this 
was not happening, the ALC voltage would 
have a sawtooth waveform, which mani- 
fested itself in a speech waveform having a 
sawtooth baseline and a variable gain from 
one peak to the next. The reason for this 
behavior is that the ALC feedback circuit, 
for desirable time constants, will pass fre- 
quencies which can be amplified by the 
amplifier stages. 

The above problem was recognized and a 
solution found some years ago (see Re- 
ference 3). If the amplifier whose gain is 
controlled has a push-pull configuration and 
the ALC voltage is applied to the tubes or 
transistors in parallel, then, as a first-order 
approximation, if the stages are perfectly 
symmetrical, there can be no AF feedback in 
the ALC loop, I have designed such a 
system, followed by an adjustable clipper 
and a low-pass filter. 

The equipment has been designed in 
accordance with the criterion of an ALC 
attack time of no more than 10 milliseconds, 
to insure reduction of initial peaks, and a 
release time of about 300 milliseconds, to 
accommodate changes in voice level and yet 
not permit the background noise to rush in 
too quickly when the voice is interrupted. 

Block Diagram 

Figure 2 is a block diagram of the 
processor. An isolation stage consists of a 
source-follower FET, offering high im- 
pedance to a microphone and driving a 
single-end to push-pull converter through a 
manual gain control. This stage drives a 



push-pull 1C amplifier with ALC, whose 
output is then converted back to single-end- 
This output drives a two-stage amplifier 
feeding an ALC voltage generator. It also 
feeds a clipper and low-pass filter. The 
clipping level and the filter output are 
controlled manually. The ALC generator 
feeds a bias-control stage which provides the 
correct bias range for controlling the push- 
pull amplifier. 

Circuit Details 

Figure 3 is the circuit diagram. The 
source-follower FET at Ql is zero biased 
through R 1 . R2 is a 9 in isolation resistor to 
prevent parasitic oscillations; Rl and R2 join 
directly at the source contact. Q2 provides 
audio voltages equal in amplitude and 180 
opposed at R6 and R7 to drive a push-pull 
stage. The push-pull, ALC-controlled ampli- 
fier Ul is an RCA type CA3028A integrated 
circuit, shown in detail with numbered 
terminals. The transistor below the differen- 
tial pair controls the gain of the system by 
means of ALC voltages applied to terminal 
2. 

The output of terminal 8 of Ul goes to 
Q3, an emitter follower used to provide a 
low driving impedance. The opposite-phase 
output at terminal 6 goes to a phase inverter 
Q4 driving emitter-follower Q5, which also 
provides low driving impedance. The outputs 
of Q3 and Q5 are now of the same phase. 
Before combining in capacitors Cll and 
CI 2, they must be equalized in amplitude. 
This was done in our case by placing an 
100,00012 resistor, R20, across R2L The 
combined audio signal, now single-ended, 
drives the two-stage amplifier using Q6 and 
Q7. 

One output of Q7 goes to the high- 
impedance input of FET Q8 so as not to 
apply a distorting load across the audio 



input 




SE TO pp 
CONVERTED 



PVSH PULL 

GAIN- 
CONTROLLED 
AMPLIFIER 



PP TO S.E 
CONVERTER 



AMPLIFIER 













BIAS 




ALC 
GENERATOR 




CON! 


rRCL 





CLIPPER 

LP 
FILTER 



-f- 



OUTPUT 



Fig. 2. Block diagram of speech processor. 



48 



73 MAGAZINE 



OUTPUT 



INPUT 




Fig. 3, Speech processor circuitry 



output of the system. Q8 is an emitter 
follower driving transformer Tl, which in 
turn drives a full wave de rectifier supplying 
the ALC voltage. The magnitude of the 
feedback voltage is controlled by R40, an 
internal 2000f2 0,1 watt trimmer pot, which 
is set safely below a point of system insta- 
bility. Insufficient response to low frequen- 
cies, as when the primary Tl is too small, 
results in too little ALC for the low fre- 
quencies and thus overall enhancement of 
lows in the audio output. 

The ALC voltage actuates Q9, a source 
follower used as bias control for the 
CA3028A. Q9's source is connected to 
terminal 2 of the latter, R43 is a high- 
resistance trimmer pot, or an experimentally 
determined fixed resistor of perhaps 220K, 
which may be needed to bring the source 
current to about 2 mA when the unit is 
idling. Higher currents made the experiment 
unit unstable, and lower currents afforded 
too little ALC, Actually R43 was not installed 
in that unit; several FET's were tried until 
one was found which gave the correct 
current at zero bias. R41 was used essen- 
tially to interrupt the dc lead at the gate 



terminal, so as to avert parasitic oscillations. 

The second output of Q7, through CI 5, is 
clipped by Dl and D2, with the clipping 
level adjusted by an external control, R35. 
At the highest resistance positions of this 
control, the diode bias voltage is above the 
level where any clipping occurs, even for the 
tallest peaks. Filtering is done by the pi 
network, CI 6, L2 ? CI 7. L2 is the same unit 
used by WB2EYZ (Reference 1). In that text 
the values of CI 6 and CI 7 were 0.005 //F. 
However, when those values were tried > the 
high-frequency roll-off was 3 dB down at 
only 1500 Hz. When 0.0015 /iF capacitors 
were used, the corresponding point came at 
2700 Hz. Neither design was strictly in 
accordance with theory. 

R38 is an externally controlled output 
potentiometer. Note that the audio voltage 
is increased by Q7 to insure good controlled 
clipping. After clipping and filtering it is 
reduced by the combination of R36, R37 
and R38, to produce outputs of similar 
magnitudes to that of the microphone alone. 

Since trouble can be experienced with rf 
feedback, microphone and other audio ca- 
bles should be short. L1C1 and L3C19 are 






JANUARY 1973 



49 



for rf filtering. The inductors can frequently 
be omitted. 

The I2V power source can be a battery 
or a well-filtered aopowered supply. The 
small imported units which plug directly 
into an ac socket work nicely. 

Operation 

The ALC behavior of the unit at full gain 
at 1000 Hz is shown in Fig. 4. The input 
reference level was selected arbitrarily as 
31.6 mV rms (10 dB above 10 mVh since 
this is near the highest value of intelligible 
speech output for the mdst sensitive micro- 
phone used in the tests, an RCA HK 107, 

The data show only a 2 dB drop in output 
for a 20 dB drop in voice level (18 dB of 
compression), and an 1 1 dB drop in output 
for a 40 dB drop in voice level (29 dB of 
compression). 

High gain settings of R3 correspond ,to 
heavy compression. But when the voice is 
interrupted, too much gain may result in the 
appearance of undesired audio signals: back- 
ground noise, hum and breathing sounds, as 
well as room echo. At top values of R35 
there is no clipping, but as values are 
decreased, the highest peaks begin to be 
clipped. For somewhat lower values, the 
intelligible portion of the waveform begins 
to be truncated and the output amplitude is 
lowered. This loss of gain must be made up 
by increasing the settings of R38. The 
system, surprisingly enough, is usable even 
with the severely truncated speech wave- 
forms observed on an oscilloscope when R35 
is set to zero, but, the more severe the 
clipping, the stronger the undesired audio 
signals relative to the desired signals. With 
reduced compression and heavy clipping, 
some undesired signals may be present all 
the time. 

Tests were made to measure the effect of 
the processed speech upon a receiver S 
meter, and to evaluate real gain in intelligible 
speech. The unit was used to modulate an 
old Viking Invader 200 watt p.e.p, trans- 
mitter driving a dummy load. For each 
setting of the processor controls and for no 
processor, the system audio gain was ad- 
justed to just below rf flat-topping. 

In testing with voice signals for the 
various conditions of the processor, 



essentially no change occurred in the S 
meter reading in an R4B receiver. This is 
attributed to the fact that the receiver AGC 
has a fast attack time, so that it gave the 
same response to a spike of the uncom- 
pressed speech driven just below flat top- 
ping, as to a burst of processed speech driven 
to the same level. Other tests gave different 
results, however. 

A well shielded receiver (Hamrnarlund 
SP-600) was connected by means of cables 
through an rf decade step attenuator to a 
few feet of wire as an antenna. For signifi- 
cant attenuator readings, the system was 
operated with never less than 20 dB dialed 
into the attenuator so that antenna always 
looked into a 50O load. The transmitter 

PARTS LIST 

Fig. 3. Components 

01,08,09 FET-1, HEP 802, 2ISI3819, etc. 

Q2Q7 2N697, HEP54 

U1 CA3028A D1-D4 IN 270 

L1-L3 2.5 mH rf choke 

L2 3,5 H miniature audio choke, UTC DOT 8 

T1 GC Co, D 1-728 transformer. For primary, use 

half of BOOH CT secondary. For secondary, use 

lOOOnCT primary. 

Capacitors 

C1,C19 0.001 JUF 

C2 0,005 jUF 

C3 0.05 flP 

C4,C5,C8,C22, 100/iF 15V 

C6, C7, C9,C10, C15, C18 O.ljUF 

C11 r C12, 10jLlF 15V 

C13 30jUF 15V 

C14, 0.02^F 

C16,C17 00015JLIF 

C20, C21 6 (IF 1,5V 

Resistors (all except potentiometers 1/2 watt) 

R1 2.2M 

R2 91-R3 1 0K audio taper pot 

R4, R16, R23, R26 180K 

R5, R17, R24 56K 

R6 ( R7 r R18 r R19, R21 r R22, R25, R34 4.7K 

R8, R14, R15, R29, R33, R41 1.0K 

R9, R11 10K 

R10, R12, R37 47K 

R13 2K 

R28, R32, 3.9K 

R30 120K 

R35 5K pot 

R36 24K 

R38 50K audio taper pot 

R39 10OK 

R40 2K trimmer pot 

R42 30K 

R20 See Text 

R27, R31 33K 



50 



73 MAGAZINE 



dummy load was fed through a T connector 
so that a few inches of wire could be 
connected to the high side as a transmitting 
antenna. 

An admittedly crude set of tests of 
listening to oneself was conducted and the 
step attenuator adjusted to something re- 
sembling equal intelligibility of processed 
speech after unprocessed speech had been 
used. With almost full ALC, the RCA HK 
107 microphone showed 5 or 6 dB of voice 
power advantage for a variety of processing 
adjustments, even though the transmitter 
already had some built-in ALC. 



40 



UJ 

£ 



UJ 

m 

a 
o 



2 

8 



30 - 



v: 

C0** i flESSl0*4 



ao ■ 



10 > 




MAXIMUM 
COMPRESSION 



10 20 JO 

INPUT. DB BELOW REFERENCE 



40 



Fig. 4. Compression characteristics: a. maximum 
compression; b, no compression. 



Another indication of enhanced speech 
power was that during transmission with 
various processor settings and with the trans- 
mitter always adjusted just below flat- 
topping by any portion of the speech wave- 
form, an rf wattmeter showed three to over 
four times the average output power of 
unprocessed speech, 

On-the-aix tests uniformly brought com- 
ments that the processed signal was better 
than the unprocessed signal, the best quality 
being with heavy compression, associated 
with fairly high input gain, and a moderate 
amount of clipping. Less compression with 
severe clipping appeared more distorted, but 
very readable, to some listeners. This adjust- 
ment seemed to some to be "the kind of 
thing to get through in a pile-up/* 

One reason the processed speech is su- 
perior to the unprocessed speech appears to 
be because the time intervals between the 
spikes of Fig. 1 are now filled with intelligi- 
ble speech, where noise or interference 



might otherwise take over. This '"fullness" is 
quite noticeable and beneficial, even though 
the speech is only of communications quali- 
ty. 

No doubt a directional or noise-cancelling 
microphone should permit the use of greater 
gain or more clipping; efforts should be 
made to eliminate sources of hum and rf 
pickup as well as of equipment audio hum. 

It is evident that with equipment de- 
signed to operate below the legal power 
input limit, the useful sideband output may 
be increased by at least 6 dB ? with compara- 
ble input increase. However, one has to be 
concerned as to whether the output-tube 
dissipation and the power-supply capacity 
will handle the extra load; i.e., the linear 
dynamic range of the output stage has to be 
the limiting factor in power-output capabili- 
ty. The author's old Viking Invader meets 
these requirements. When a linear final 
amplifier is used, legal limitations make it 
necessary to see, in the United States, that 
the average input does not exceed 1 kW 
under processing conditions, 

Conclusions 

The speech processing unit described 
above offers the user a flexible modulation 
system with the capability of controlling a 
number of parameters in order to optimize 
transmitter output in accordance with the 
user's voice and operating habits, and the 
characteristics of the rf equipment he is 
modulating. It should be especially useful in 
"beefing up" low-power gear. The effective- 
ness of all solid state transmitters should be 
enhanced by incorporating speech processing 
circuitry similar to what has been described. 

. . .W0YBF 

References 

1,JJ. Spadaro, WB2EYZ, H A solid-state 
speech processor," QSTNov. 1969, repro- 
duced in "Single-sideband for the radio 
amateur," ARRL, Inc., 1970. 

2, H.G, Collins, W6JES, "Ordinary and pro- 
cessed speech in SSB application/ 1 QST 9 
Jan, 1969, reproduced as above. 

3. E.W. Pappenfus, W,B. Bruene and E.CK 
Schoenike, "Single sideband principles 
and circuits," McGraw-Hill 1964. 



JANUARY 1973 



51 




4 rO£fG//U7Ti£ j&& 



*+ 



R. L. DRAKE CO. 
504 Richard St, 
Mi amis burg, Ohio 



Gene C. Berrier K5RTA 
7 216 Turner Terr, 
Ft, Worth, Texas 7611 



Gentlemen; 

Just have to drop you a note and tell you what a tough little rig 
the TR-22 is. I have been using mine mobile in the car and on my 
motorcycle and portable at the office. 

Yesterday, I had it strapped to the luggage rack on the motorcycle 
and was working motorcyle mobile on the way to work. Unfortunately, 
I took a new road that turned out to be rougher than anything I had 
previously been on with the radio , I suddenly caught sight of the 
TR-22 in the rear view mirror bouncing along the pavement behind me. 
I was doing about about 40 MPH and was dragging the TR-22 by the 
mike cord. I drug it for at least a block before I stopped. 

The carrying case was pretty torn up and the antenna was snapped off 
right at the case. I returned home and hooked it up in the car and 

it works like it always did. 

The TR-22 certainly lived up to all the expectations 1 had for it 
after owning the TR-3 and RV-3 for many years. 





Cene C. Berrier 



R. L. DRAKE COMPANY 





But you don't have to take Gene's word 

aet 1 TR m '" ^ h3PPV to See that V° u 
get a I H-^2 so you can try it 

yourself. At your distributor: 



540 Richard St., Miamisburg, Ohio 45342 
Phone: {513) 866-2421 • Telex : 288-017 



Hank Olson W6GXN 
P.O. Box 339 

MenioPark CA 9402S 




WO -TON 



TESTG 




RATOR 



I - n the testing of amplifiers and other 
devices associated with Single Sideband 
systems, the two-tone test has achieved a 
great degree of acceptance. Regardless of 
how the test is performed, whether looking 
at the output of the device under test with 
an oscilloscope (amplitude vs time) or with a 
spectrum analyzer (amplitude vs frequency), 
the basic input requirement is two good sine 
waves. In the laboratory, such a two-tone 
signal is usually obtained by using two good 
quality audio oscillators, like the Hewlett 
Packard 204C, and a resistive adding network. 

In amateur testing, two-tone audio test 
signals are usually of much poorer quality, 
being derived from mike-preamps switched 
into oscillation by various types of frequen- 
cy-dependent feedback networks. 1 Even 
commercial "station monitor" systems often 
use only a pair of simple phase-shift oscilla- 
tors (without negative feedback or auto- 
matic amplitude control). Although such 
simple methods of obtaining test tones are 
useful, they often yield test tones in which 
each sine wave contains appreciable distor- 
tion (contains harmonics), and this lack of 
purity can be incorrectly ascribed to distor- 
tion in the system under test. Basically, what 
it comes down to is that if your input tones 
aren't pure, you can't really tell how much 
distortion is from the test tone generator 
and how much is from the system under 
test. A really good two-tone test generator 
will help us to * "separate the sheep from the 
goats. 

The two-tone generator described here 
uses two of the same basic Wien Bridge 
oscillator circuits as are used in most labora- 
tory-type audio generators- However, by 
using modern Integrated Circuit (IC) Opera- 



tional Amplifiers (op amps), each Wien 
Bridge can be built around a single semi- 
conductor package. Op amps are also used as 
active bandpass filters to further clean up 
harmonics of the two oscillators, and to sum 
the two pure tones. The block diagram of 
the generator is shown in Fig. 1. 

The particular oscillator circuit used is a 
form of Wien Bridge originally described by 
Bob Botos of Motorola. Its charm is that he 
uses a pair of back-to-back silicon diodes as 
the non-linear control element. Such a pair 
of silicon diodes is probably much more 
readily obtained, and less expensive 9 than a 
particular light bulb or thermistor — as used 
in most Wien Bridge circuits. The diodes 
prove to be very effective as non-linear 
elements; and they do not cause severe 
waveform clipping because of the 47 K resis- 
tor in series with them. The IK pot that is in 
the same arm of the bridge as the non-linear 
diode elements (R I or R2), is used to set the 
oscillator level. This pot should be set to give 
a 10V peak-to-peak output at T.P. I (and 
T.P. 2), 

The active bandpass filters that follow 
each audio oscillator are described in detail 
in References 3 and 4. The use of this form 



AUDIO 

OSCILLATOR 

HQA 




BANDPASS 
FILTER 
































OPERATIONAL 
ADDER 












1 


i 






AUDIO 

OSCILLATOR 
NO. 2 


BANDPASS 
FILTER 


1 







Fig. I. Block diagram of the tone generator. 



JANUARY 1973 



53 



of active bandpass filter as a single-control 
variable-frequency audio filter is apparently 
due Bob Dobkin. 5 An idea of how a filter 
composed of nothing much more than R's, 
C\ and an operational amplifier can have 
selectivity, can be gained as follows. The R-C 
network that controls the frequency is con- 
nected between the output of the op amp 
and its inverting input - that is, in the 
negative feedback path. The R-C network is 
reminiscent of the bridged-tee null network. 
At the network null frequency, the negative 
feedback is the lowest, and therefore the 
closed-loop amplifier gain is the highest. The 
frequency of the passband is adjusted by 
means of the 1 K pot in the R-C network to 
match the oscillator frequency. (Adjust R3 
for a maximum 2000 Hz output at TJ\ 3, 
and adjust R4 for a maximum 800 Hz 
output at T.P. 4.) 

The particular IC op amps used in the 
active bandpass filters are LM301A*s by 
National Semiconductor. These op amps are 
compensated in a way referred to as the 
"feed-forward" method of compensation. 
This way of compensating op amps allows 
them to have higher slew rates than with the 
normal single-capacitor compensation 
usually used with LM301A'S. The "feed- 



forward" compensation method is described 
at some length in Reference 6, Because this 
type of compensation is used in the active 
bandpass filter op amps, it would probably 
not be too good an idea to use other types 
of op amps here. The op amps used in the 
oscillators and operation adder, however, 
can be any of a variety of types. The 
MCI456 of Motorola or fiA14l of Fairchild 
should serve well in these positions (with the 
33 pF compensation capacitors omitted). Of 
course, there are a number of exact equiva- 
lent of the LM3Q1A, MC1456, and tiA74l 
made by a variety of companies other than 
the originators these are not to be con- 
sidered replacements but second sources. 
One could probably even use juA709's if he 
understands how to properly compensate 
them (and wants to go to all the bother); but 
if you are at all uneasy about substitutions, 
use LM301A's throughout and the circuit of 
Fig, 2. 

The last stage is the operational adder, or 
summing amplifier. This op amp is operated 
at a closed-loop gain of 1. The summing 
point of the two pure sine waves (2000 Hz 
and 800 Hz) is at the inverting input of the 
op amp, As connected, this port is a 'Virt- 
uaT* ground; if you look at this point with a 




OJOUT 



ISOpF 



Fig- Z Schematic diagram of the two-tone test generator utilizing Wien Bridge oscillators. 



54 



73 MAGAZINE 



HE PI 76 
(OftEOUflU 




I 




j*A7ai2 



lir ^a«^J 



4 7pF 



-* *IZV 




-*■ -IZV 



TA*JT 



2N5194 



Fig, 3. Dual voltage regulated supply used to power the tone generator. 



scope you will see nearly zero voltage. This 
is simply because the (high gain, 80 dB) op 
;irnp strives to keep the differential voltage 
between inverting and non-inverting input at 
zero, and so the non-inverting input is 
effectively grounded. So each sine wave 
"sees"' the summing amplifier as I OK to 
ground; and the two sine wave generators 
cannot interact with each other to cause 
distortion. The summing amplifier is a true 
algebraic summer, which is why operational 
amplifiers thus connected were originally 
used in analog computers. If one sine wave is 
instantaneously at +5V and the other is :«t 
3V, the output will be +5 -3 = +2V. And 
since there is no coherence between the 
2000 Hz and 800 Hz sine waves, we can 
expect to see plus and minus voltages as high 
as twice the peak value of each sine wave 
(±10V peak, or 20V peak to peak). This 
should be more than enough level for most 
two-tone testing. The level of each sine wave 
can be controlled by the 1 Meg pot at the 
input to each active filter (R5 and R6). 

Measurements of the output of the two- 
tone generator described above, with a 
General Radio I900A Wave Analyzer, show 
that (for equal level tones) the harmonics 
and cross products are all down more than 
70 dB from the desired tone. This sort of 
purity should be more than adequate for 
testing any amateur communication system. 

A simple, but well-regulated power sup- 
ply for the two-tone test generator is shown 
in Fig. 3, An integrated bridge rectifier is 
used with a center-tapped secondary trans- 



former as a plus and minus full wave 



rec 
of one 
term i n a 1 
MA7812. 



Plus 12V is simply obtained by use 
of the new fixed-voltage three- 
regulator ICs of Fairchild, the 
This \C looks like a plastic power 
transistor (UGH 7812 393) and its common 
terminal is the heat sink lab. So screw it 
right to the chassis if you want to - with no 
mica washers, grease, etc. 

The negative regulator is slightly more 
complicated, but still simple The National 
Semiconductor LM304H is used, with the 
regulated +1 2 serving as its reference voltage. 
In this way the plus and minus voltages 
track A 2N5I94 plastic power PNP transis- 
tor is used to increase the current capability 
of the LM304H. The 2N5194 must be 
heat-sinked in a conventional way, using 
insulating washer, etc , if the chassis is used 

as the heat sink. 

. . .W6GXN 
References 

1. A.R.R.L., "A Simple Audio Oscillator for 
Tune-up, Single Sideband Tor the Radio Amateur, 
Third Edition, 1962, p. 144. 

2. Botos, R M "Breadboard Techniques for Low 
Frequency Integrated Circuits Feedback Ampli- 
fiers/* Motorola Application Note AN 271, October 
1 966. 

3. Burr-Brown Handbook of Operational Active 

R-C Networks, 1966. 

4. Doyle, N., tL SwifL Sure Design of Active 
Bandpass Fitters * EDN. Vol 15, No 2, January 
15,1970. 

5. Dobkin. R., 4 *Easily Tuned Sine Wave Oscilla- 
tors," National Semiconductor Linear Brief I B-16, 
March 197L 

f>. Dobkin, R., "Feedforward Compensation 
Speeds Op Amp," National Semiconductor Linear 
Brief LB-2. March 1969. 



JANUARY 1973 



55 




BRIBERY LEGAL? 



' J?*i*^ 









IMPOSSIBLE OFFER? 

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reading it wilf be, we hope youll agree. And 
the more circulation 73 has the bigger the 
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In the hopes of making subscribing so 
attractive that it just cannot be passed 
up - whether it be for yourself or a friend, 
we are offering the below selection of books 
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— any book. Does that look like a good 
deal? 

FREE BOOKS 

Any one of the following books is avail- 
able (postpaid) as a premium if you buy a 
subscription to 73 for yourself or a friend 
(or an enemy — or even an ARRL official 
since few of them get ith One book per 
subscription. 



A The Novice Gla& 

License Study Guide has 
not yet been published in 
73 or m any other maga- 
zine, This book contains all 
the basic technical inform- 
ation needed to pass the 
Novice License with flying 
colors — and is invaluable 
as a basic text for under 
standing the General Class 
Study Guide. Profusely il- 
lustrated and so clearly 
written (hat just reading it 
is enough to permit most 
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B The 73 General Class 
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whack, isn't it foolish not 
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tor preparing to pass the 
Advanced Class license 
exam. Never before has 
radio theory been made so 
simple. After just reading 
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And remember that in ad- 
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ory seem simple, A little 
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E The 73 DX handbook 
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glus articles on working 
>X on the different bands. 
There are great circle bear- 
ing maps and charts, and 
more . r , more . . . more. 



AMATEUR RADIO 

GENERAL 

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MORESMORE BOOKS 




F The FN! Anthology has 
reprints of all the articles 
and technical data from 
the early issues of the FM 
Journal. Ho FM library is 
complete without this 
data, much of it fust not 
available elsewhere. S5.95 
value. 




tl The BEST of FM is a 
compilation of the best ar- 
ticles that appeared in the 
FM Joumal from March 
1968 through June 1969, 
the last of the magazine. 
Read the extremely con- 
troversial Chronicles of 76, 
Pius dozens of technical 
and circuit articles avail 
able nowhere else. $4.96 
value, 



SOUD-STATI PROJECTS 
w tat tjjwimdb 




J Solid State Projects for 
the Experimenter contains 
over 60 projects taken 
from the pages of 73 Mem* 
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Converter. Or, maybe a 
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fet fariitiiig 

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is an introduction to radio 
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gives you some of the his- 
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tion and an idea of what 
you can expect from your 
new hobby, $3,95 value. 




L IC Projects for Amateur 
& Experimenter is an an- 
thology of IC construction 
projects taken from 73 
Magazine- Edited by 
Wayne Green, it's a must 
for any ham library. $3.95 
value. 



MONTHLY GIFT 

If you have a friend who might 
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Your gift will start with the next 
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You pet the book - if you like. If 
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again with your compliments- What- 
ever turns you on. But if you give the 
gift subscription you certainly rate the 
book yourself. 




OR BACK ISSUES? 

Where can you buy a one year subscrip- 
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is a fabulous deal. It is such a good deal that 
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ber his kindness with a 73 subscription. 



WHY THIS OFFER? 

The whole purpose of this offer is to 
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It is obvious that it is not possible to send 
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This offer is valid for one year subscriptions 
only. 



56 



73 MAGAZINE 



FREE HANDBOOK 

1200 PAGES! 

Where else can you get an amateur 
radio handbook for free? That's right, 
you get about 1200 pages of articles 
in 73 every year and the magazine is 
designed so that each and every article 
is on separate pages — and 73 is the 
only magazine that does this — with 
no flipping to the back of the maga- 
zine for a parts fist or anything. Every 
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together by subject into a giant hand- 
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magazine has anything (ike this avail- 
able. 

ACTIVE EDITORS 

Only one ham magazine of the four 
has editors that are active and on the 
air— and have been for years. 73 has 
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magazine staff that has done this. 73 
has its own mountain top laboratory 
for VHF — the only ham magazine 
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television — the only magazine to do 
this. 73 goes on DXpeditions - the 
only ham magazine to do this. 73 runs 
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And what difference does alf this 
make? Perhaps you've noticed that 73 
is more involved with the hobby — 73 
not only reports the most interesting 
news, sometimes it helps to make the 
news. It helps 73 to be more fun to 
read, to attract better authors for 
articles, to bring you more valuable 
information on the newest of ham 
products. 

Which ham magazine was the first 
to report on the first commercially 
made two meter synthesizer? 73 of 
course. And which got the first new 
units made by Genave? And which got 
the first Clegg units? The first Inter- 
national Signal units? The first Drake 
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73 NEWS PAGES 

You'll enjoy the monthly news 
reports on what is going on in the 
hobby — new products — political 
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news — Slow Scan news — VHP 
news — FCC news, etc. 73 is- the 
ONLY ham magazine to cover the 
news of amateur radio in this easy to 
read manner. Keep really up to date 
with the 73 newspages, 



f3 MAUA^INb PE 



Name 



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. 73 MAGAZINE PETERBOROUGH NH 03458 

P^^^ ^^™ ^^^ m ^^^ fc«*»^— ^ . ^^^— ^^^— ^^— « -tm^^m ^mt^m h^^h* —^^m ^^^_ ^^^^ ^^^^m -^^^—m ^^^^m ^^^v ^^m 



EDITORIALS 

The editorials in 73 pull no 
punches. Nothing wishy-wshy. It is 
safe to say that unless you read the 
editorials in 73 you cannot know 
what is really going on in our hobby. 

Did you enjoy the article in August 
on the DXpedition to Navassa? This is 
one of the reasons that 73 is dif- 
ferent — it is involved. The editors get 
out there and operate, go on DX- 
p editions, organize them 
even — organize ham tours — set up 
repeaters — work in the con- 
tests — work lots of DX — are actually 
on slow scan — on RTTY — it makes 
the magazine come alive. When the 
editors write about something you 
know that they have the background 
to bring you the inside scoop. 



HOW TO SUBSCRIBE 

If you prefer not to shred your 
copy of 73 there is no real reason why 
you should not put the subscription 
information on a separate piece of 
paper, on the margin of a hundred 
dollar bill, or whatever turns you on. 
Regular subscriptions ordinarily 
start with the next published issue of 
73. If you want otherwise just indi- 
cate same on the order. 

The regular subscription rate for 73 
is $6 for one year, $1 1 for two years, 
$15 for three years in North America 
and $1 extra per year for foreign 
subscriptions. 

The recent serious rise in postal 
rates will be forcing 73 to increase the 
subscription rate soon - don't say 
you weren't warned. 



AMATEUR RADIO IS MORE FUN WHEN YOU READ 73! 



JANUARY 1973 



57 




I 



BRIGHTNESS 



OFF 



HOR. HOLD 




CONTRAST 




3l 



SSTV MAKES YOU 
FEEL YOUNG AGAIN! 

Remember the excitement and enthusiasm you 
felt when you first started in amateur radio? Doz- 
ens of hams have told us that working SSTV has 
renewed that same thrill and enthusiasm. In fact, 
they become so fascinated, and enjoy working 
SSTV so much that they stay up half the night 
working other SSTV stations. Now, when was 
tht hist time you got that excited over amateur 
radio? 

Order your Robot SSTV equipment now, and get 
in on the fun. Or, write for the full SSTV story. 
But do it today, 

Please send your new factory direct price list. 

Enclosed $. - Please send the following 

equipment via AIR n or SURFACE n 

Model 70 Monitor $295 

Model 80 Camera $295 

□ 25mm M.4 MACRO Lens $54 






! 









Call 



State 



Zip. 



California residents add 5% sales tax. 



I 



ROBOT RESEARCH INC. 

7591 Convoy Court San Diego, California 92111 




* EE 2£ UsSEst* 



^0>N 



tHt 



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- w v,o^ cW?uW 









«»■ &0 °\ r rio l* 5 oft 5 W *»£ MOD fc -cR 



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$1^0 



00. 



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3 ic**£tf>: «^^&S£*^ - . 



SUP 6 " "..of at 






eRgL CVJ» a o"599S< 






uo»»^5.00 * e 



oo^i°A"599« a, : s ; 






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t&J$»ya» l 






ftuW* 1 



W. R. Carruthers VE3CEA 
256 Alexandra Avenue 
Waterloo Ont. Canada 



SPECULATIONS 

FUTURE DX 




Most radio amateurs in the world know 
that the sunspots control ionization 
of the upper atmosphere, hence DX propaga- 
tion. But not many of them pay much 
attention to propagation — amateur radio is 
their hobby and they either "get through 57 
on a QSO or they don't. If conditions are 
"bad" they accept the situation and work 
contacts closer to home. 

There are a few amateurs, however, who 
are definitely interested in the sunspots in a 
scientific sense and the relationship to DX 
propagation. These men wait for the Zurich 
Solar Observatory results each month and 
carefully watch the various forecasts. Like 
these men, I have been interested in the 
sunspots for many years and each month 
plot the results from Zurich. 

We have some history of the sunspot 
counts since 1 749; This article considers this 



past history, and speculates on what that 
history may be trying to tell us. It also 
speculates on what the sunspot story might 
be in the near future and correspondingly, 
what DX propagation might be. Some sug- 
gestions are included as to how amateurs 
might cope with low DX propagation condi- 
tions. 

Figure 1 shows the past history of the 
sunspot counts. It is plotted by years using 
the 12 month running smoothed sunspot 
numbers on the vertical axis. Years are used 
on the horizontal axis. Also shown are the 
cycle numbers, from 1 to the present cycle 
20, which will end about the middle of 
1975. 

Before looking at Fig. I in detail, let us 
agree that the results shown are not finite. 
They are the results of telescopic observa- 
tions of the sun made by numerous o fo- 



ot 
u 

a 

r 

3 



W 

O 

la 



3 
X 

X 
I- 

z 

c 

Z 

w 




I7S0 60 
CYCLE I 



70 



80 

3 



SO 



1800 10 



20 



30 AO SO 60 

6 7 8 9 IO 

Fig 1. The 1 2 month running smoothed sunspot 



60 



73 MAGAZINE 



servers. Since the sunspots themselves may 
only last for a short interval of time, counts 
between observers may vary. This was recog- 
nized in 1849 by Rudolf Wolf, Director of 
the Zurich Solar Observatory, when he 
developed the formula to care for the 
variations in observers, their equipment and 
their observations. His formula is still in 
effective use today. So we will not concern 
ourselves, in general, with the actual sunspol 
numbers, but rather look at the broad 
picture presented in the past history avail- 
able to us- 
No w, looking at Fig. 1 we note some 
interesting points — 

1. Cycle 1 seems to start increasing 
activity on the sun's surface. Cycle 2 was 
greater; cycle 3 quite high, then the activity 
fell off. Cycle 4 was lower and cycles 5 and 
6 quite low. After the activity of cycles I, 2, 
3 and 4 did the sun ^rest" from 1798 to 
1823, about twenty-five years or so? 

2. In cycles 1, 8. 9, 10 and I 1 there was 
an increase in activity, but seemingly of a 
random nature. Cycles 12, 13 and 14 were 
much lower in activity, but higher than 
cycles 5 and 6. Was the sun's thermonuclear 
reaction "resting* 1 again after the activity of 
cycles 8, 9, 10 and 1 1? 

3. In cycle 15 increased activity took 
place, but this may again have been of a 



random nature since cycle 16 decreased 
considerably following it, 

4. Cycle I 7 started off fairly high, follow- 
ed by increased activity in cycle 19, Cycle 
20 seems to have repeated the falling off of 
cycle 4, although of somewhat lower value. 

In all our thinking on these points there 
are several thoughts we must keep in mind — 

1. We cannot expect to develop anything 
more than generalizations from the past 
history of the sunspots since we have only a 
little more than one complete overall cycle 
of operations of the sun to consider. 

For our purposes we may consider one 
complete overall cycle as being the length of 
time from one maximum cycle to the next 
maximum cycle. For example, this could be 
the length of time between the maximum of 
cycle 3 to the maximum of cycle 19, or 
about 178 years. 

2. We have only one overall cycle to 
analyze and in the history of the individual 
cycles we have only 19. There is no regu- 
larity to the individual cycles. The average 
cycle appears to be 1 LOS years. The indi- 
vidual cycles may vary widely (see Fig. 1 ), 

Some Fourier analysis studies were made 
in Washington some years ago and tended to 
indicate a secondary cycle of about 
160-170 years in length. However several 
overall cycles, say at least 2, or 320-340 





to 



SO 



SO 1900 10 

11 12 13 14 

numbers plotted by years from 1 750 to 1 971. 



20 


30 


40 


50 


60 


70 


15 


16 


17 


IS 


19 


£0 



80 



JANUARY 1973 



61 



JAN 
1936 



200 — 



160 — 



1D0 



8 



i 




JAN 
1760 



YEARS FROM ZERO - FOR CYCLES 17-1B-19 
2 4 6 9 10 12 H 16 

1 



IB 



20 



22 



I 



r 



24 

"1 



09 




Y = 4-29X + 7B-1 



LINE FOR 
CYCLES 1-2-3 



m 
to 



to 



i 



2 A 6 3 10 12 U 

YEARS FROM ZERO- FOR CYCLES 1-2-3 



16 



IS 



20 



22 



-J 
24 



Fig. 2. "Lines of best fit. See text. 



years, with associated records, must be 
obtained before we will be able to conclude 
there is this overall cycle in addition to the 
1 1 year (approximate) cycles. 

The increases shown in cycles 1 , 2 and 3, 
17, 18 and 19 seem too similar to me to be 
discarded in our thinking. Let us look at 
them in more detail. To simplify the 
mathematical work, only these cycles will be 
considered. 

If we lay a straightedge along the peaks of 
cycles 1, 2 and 3 and the same on cycles 17, 
18 and 19 the "line of best fit" for each 
group seems to be at about the same slope. 

The next step is to check these 'lines of 
best fit 7 ' for each group, using the usual 
mathematical procedures. To do this we 
must establish "zero dates* for the 
mathematical procedures. For cycles 1, 2 
and 3 I have used Jan. 1760 for the zero 
date, in order to find the equation which 
represents the "line of best fit" for them. 
Similarly, Jan. 1936 was chosen for cycles 
17, 18 and 19. 

After completing the mathematical work 
we find we have developed two equations — 



Cycles 
1 , 2 and 3 
17, ISand 19 



Equation 

Y = 4.29 X + 78.1 

Y-3.90X+ 1 10.9 



These equations represent the lines of 
best fit. In themselves they do not show 
what we want — they must be charted to 
show their relationship. This has been done 
in Fig. 2. 

Examination of this figure indicates the 
lines to be nearly parallel. Differences in 
counting the sunspots by the various obser- 
vers around the world could account for the 
small amount by which the lines are not 
parallel. This is not significant to us, what 
we are interested in is that the lines are 
nearly parallel. 

So the sun, in its activity in cycles 1, 2 
and 3, almost duplicated that activity in 
cycles 17, 18 and 19. Improved telescopes, 
more trained observers and better observa- 
tory conditions might account for the fact 
that more sunspots were counted in cycles 
17,18 and 1 9 than in cycles 1 , 2 and 3, 

This brings up the question, could this 
indicate a regularity in the sun's behavior? 
Does the sun's activity peak every 1 60- 1 80 
years, then a short resting period follow? To 
obtain an answer to this question we must 
have more evidence, more complete data on 
the sun's overall cycles. 

Another question might be asked. After 
each burst of activity of the sun, does a 
resting period always follow? If this is true, 



62 



73 MAGAZINE 



then cycle 21 could be quite low in activity, 
with a maximum annual mean of about 

40-45. 

Fortunately we will be able to estimate 

quite soon what cycle 2 1 will be like. Cycle 
20 is expected to be complete about the 
middle of 1975 and then cycle 21 will start. 
If it will be a major cycle, it should start up 
and increase quite rapidly, month by month. 
If it is going to be a low cycle, it will 
increase quite slowly, month by month. The 
first year should "tell the tale"; i.e. by 
midsummer of 1976 we should have a fairly 
good estimate of the maximum activity 
expected for cycle 21. The maximum should 
take place about the middle of 1979. 

What we will watch for is the '*rate of 
change/" Figure 3 shows an example of this 
action Cycle 19 has been plotted for a few 
years to show the fast rise in the first few 
years (up to a maximum of 201 ). Cycle 20, a 
lower cycle of maximum 11 1, is also plot 
ted. Note the difference in the rate of 
change in the early years. 

Some of the other cycles also show this 
quite clearly, for example — the fast rise in 
cycle 3 compared to the slow rise of cycle 6. 

If my analysis is reasonable and the sun 
does rest after a period of activity, then we 

Years - Cycle 19 

55 I 56 | 57 




■Cycle 20 



I 64 



65 I 66 I 67 I 68 
Years-Cycle 20 



Fig v 3, Rates of increase for a small and large activity 
cycle. 



might expect one or two low sunspot cycles 
to follow cycle 20, These could last anything 
up to, say, 25 years in length. In this case, if 
it is to happen, there could be some things 
we should be starting to do now to get ready 
for low sunspot activity. Some of the things 
we might do are as follows - 

1. More listening for DX openings. These 
could last only a few hours — take advantage 
of them in the time they are available. 

In his book lonispheric Radio Propaga- 
tion Kenneth Davies, of the National Bureau 
of Standards ) makes the statement 'The 
daily values of R vary betweeen and 355 
or more." Imagine the band openings for a 
short time if there was an R figure of 355! 

Most DX amateurs know of the possi- 
bility of these openings. One day last sum- 
mer a station in the Indian Ocean was 
putting a 59 plus 10 dB signal into North 
America, The condition lasted for just about 
two hours, I haven't heard him since. 

So let us watch for these openings, even if 
they are of short duration. 

2. If the sun rests after a burst of activity 
then there will be fewer disturbances, 

3. On 10 meters I would expect definitely 

reduced working hours. 

4. A fair reduction of good openings on 
15 meters. 

5. 20 meters may expand in working 
time . 

6. 40 and 80 meter openings should 
expand. 

7. Work should be done to increase the 
height of the average beam or quad an- 
tennas, to obtain the lowest forward angle of 
radiation. 

8. We should all make an effort to help 
the cause of amateur satellites and learn how 
to use them effectively. 

9. Our operating procedures could be 
improved. 

The amateurs living today are fortunate 
to have been through the past years and to 
have had the opportunity of working during 
cycle 19, What will happen to the sunspots 
in future years is a function of time, It will 
be most interesting to continue to follow the 
monthly sunspot numbers from Zurich and 
ultimately to determine whether or not 
some of our conclusions are correct, 

. . .VE3CEA 



JANUARY 1973 



63 



The winning combination 



Tf^i 



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from ADIRONDACK RADIO SUPPLY, INC. 

A remote receiving V.F.O. has been added to the 
Inoue IC-21 making a winning combination two 
meter station. 



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To introduce the new Inoue IC-21 VFO and IC-21 
package, we are offering a special introductory 
deal. Send us this ad and we will ship the Inoue 
IC-21 and Inoue IC-21 VFO prepaid for only 
S450.00 complete. 

This is a savings of $59.00 over the regular price of 
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VFO. 



your order today to 

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185 West Main Street 

* 

Amsterdam, New York 12010 
N. Y.S. residents add appropriate sales tax. 



64 



73 MAGAZINE 



Vern Epp VE7ABK 

Box 371 

Nelson, British Columbia 

Canada 







How would you like a test set with the 
following features: 

1 . Frequency meter for the receiver as 
well as transmitter. 

2. Signal Generator with calibrated out- 
put. 

3. Deviation checker (with associated 
equipment). 

The need to build up a compact unit came 
after carrying some heavy test equipment up 
to a remote amateur repeater site. This test 
set will also be very handy for checking and 
aligning your two meter mobile or base 
station. It is also useful for checking out 
commercial mobiles if the frequencies are 
compatible. 

Theory of Operation 

The crystal oscillator uses one transistor 
Ql which is rich in harmonics up to about 
450 MHz. The output of which is varied by 
using a potentiometer to vary the supply 
voltage, A crystal that will multiply out to 



JANUARY 1973 



65 



the desired frequency is inserted and put on 
the exact frequency with variable capacitor 
CI. This unit in conjunction with an ex- 
ternal variable attenuator provides an ac- 
curate if signal source. The mixer consists of 
the emitter-base junction of a VHF silicon 
transistor to combine the output of the 
crystal oscillator with a small portion of the 
output of the transmitter to be checked. An 
audible beat will then be heard out of the 
audio amplifier for frequency adjustments if 
necessary. The crystal calibrator generates 
outputs every 30 kHz and is derived from a 
3 MHz crystal oscillator and two divide by 
10 ICs to give the 30 kHz markers. The 
harmonics of this device are usable to over 
150 MHz. A receiver can thus be put on 
frequency provided that the receiver is 
operating on a standard 30 kHz spaced 
channel. The transmitter can be put on 
frequency indirectly, a receiver on the same 
frequency is first put on frequency with the 
calibrator. The crystal oscillator frequency is 
then compared and adjusted using the re- 
ceiver. The transmitter to be tested now is 
mixed with the crystal oscillator and put on 
frequency by listening for a zero beat. 
Deviation can be checked out in conjunction 
with a* receiver and a dc scope. The crystal 
oscillator is first calibrated 15 kHz below 
and above the desired frequency. The output 
of the receiver discriminator is attached to 
the vertical input of the oscilloscope. The 
scope can now be calibrated and the trans- 
mitter deviation can be checked. 



V 

^s BNC 
7T* CONN 




OUT 



47 j>F 



* 



y i5K 

¥ LINEAR 




CRYSTAL 
CALIBRATOR 



+ 3J3V 



R F OUT 

BNC CONN. 

— > 



XTAL. 
CAL, 



XMTR. 
FREQ. 
TEST 



n 



„+9V 



\OQpF 
25 V 



uov. 

IN4728 
33 V IW 




Fig. I. Overall block diagram and mixer details. 

Construction 

The complete unit measures only 614 by 
AVa by 3 l /z inches. Four separate PC boards 
were used for building the crystal oscillator, 
amplifier , power supply, and the crystal 
calibrator. The overall block diagram is 
shown in Fig. 1. The crystal oscillator 
schematic and board are shown in Fig. 2A 
and B. The frequency of the unit isne not 




■o OUTPUT 



RFC 

Z-144 

OHMITE 



■Q+9 VOLTS 



/77 



o— 



fT7 



Fig. 2a. Schematic of the crystal oscillator. 



66 



73 MAGAZINE 



MFC 603O 
(MOTOROLA) 




BRIDGE 

RECT. 

MODULE 

.5 A 



*+ 



o + 



+ 



JOOjiF 
" 25V 




STANCOR 
P-8391 



Fig. 4a. Power supply schematic. Voltage can be 

varied by changing the R1/R2 ratio. 

tor. The schematic and P*C. board are shown 

in Fig, 4 A and 4B. 

Operation 

The crystal calibrator can be used to 
check any two meter channel provided it is a 
standard 30 or 60 kHz spaced one. To 
determine if the frequency to be checked is 
standard just divide by 30, It must work out 
evenly; e.g. (146,94 will divide by 30). The 
receiver padder can now be adjusted for a 
zero discriminator reading. The transmitter 
is checked indirectly by using another re- 
ceiver and the crystal oscillator. Suppose 
that you would like to check the frequency 
of a transmitter on 146.94. You must first 
apply the calibrator to the receiver and 
verify that the receiver is on frequency. Next 
a crystal with the right multiplication is 
inserted in the test set and adjusted on 
frequency using the calibrated receiver. A 
short piece of coax is placed near the 
transmitter to be tested and adjusted for a 
zero beat (switch to TX frequency). 

Deviation Checks 

Deviation can be checked in conjunction 
with a receiver and a dc scope. First the 
crystal oscillator in the test set must be 




Fig. 4b- Full size layout of power supply board. 

calibrated against a good standard for a 
frequency phis or minus the desired fre- 
quency. A calibration chart can be made up 
for each crystal desired. The output of the 
test set is now applied to the receiver. The 
discriminator output of the receiver ft ap- 
plied to the vertical input of the scope. 
Vertical calibration is accomplished by mov- 
ing crystal oscillator from desired frequency 
to plus or minus 15 kHz for a reasonable 
scope display. The scope is now calibrated 
and modulation can be applied to the 
transmitter under test. 

Calibrated rf Generator 

The crystal oscillator in the test set in 
conjunction with an rf attenuator can be 
used for an accurate calibrated rf source. 



/iV .1 



z 



3 4 .5 £ JflSl 



n 



*m 



yV ACROSS 50 -TL 



3 4 56789JO 



ill 



20 30 40 5060 80 100 

1 I 



I 



I 



I 



] 



( 



I 



1 



dBm 



TTT 



-150 
-120 



TT 



TTTT 



-140 
-HO 



130 

■100 



TTTT 

-120 
-90 



ITTT 



NT 



110 
90 



DECIBELS BELOW I WATT 



Fig, 5. Chart to be used in conjunction with the crystal oscillator and an rf attenuator. 



TT 






-100 
-70 



68 



73 MAGAZINE 



XTAL 




Fig, 2b. Full size layout of crystal oscillator P.C> 
board. 



with CI variable capacitor which is rotated 
using a vernier dial. Switch SI can have as 



many positions as desired. It is advisable to 
mount one of the crystal sockets on the 
front paneL The output level is adjusted 
with a 15,0000 pot and should be linear 
taper for smoother output variation. 

The audio amplifier uses a TA300 IC to 
produce about 1 watt output. The speaker 
used came from an old transistor radio. Any 
high gain amplifier could be used here. A 
VHF silicon diode is required for the mixer. 
One was not readily available so the E-B 
junction of a 2N3563 transistor was used. 

The crystal calibrator schematic is shown 
in Fig. 3. The unit is available in kit form. I 
priced out the individual components and 
found that it was less expensive to buy the 
kit than buy components individually. The 
MC-724 IC serves as an oscillator and ampli- 
fier. Two MC-780 are used and serve as 
dividers which divide by 10. The unit can be 
calibrated against an electronic counter or 

against the 1 5 MHz WWV signal. 

The power supply provides a regulated 9 
volts using a Motorola MFC 6030 IC regula- 



rs pF 



» 



8-50 pF 



3 MHz 



~E 




1/4 
MC-724 



,005 



J 




1/4 y* 

MC-724-P, 



3 



22 K 






13 



1/4 

MC-724-* 





A, 



MC-780 P 

H- BY 10 

IC— I 



II 




25 pF 



^ 



*® WWV 



8 




A? 



MC-780 P 

~ BY 10 

IC — 2 



IOO pF 
25 V 



27-n.2W 





iol 



1/4 
MC-724-P. 




25 pF 



t 



-© RCVR 



TO 9 VOLT SUPPLY 
THROUGH SWITCH 



Fig, 3. Crystal calibrator schematic. No P.C board layout is given but boards are available from the 
source given in the text. 



JANUARY 1973 



67 



FEEDBACK 300a 2£a 
CONTROL V V V ^rtrt^n 



INPUT 




tt CAN USC TOTAL FtXED R OF 6.2K, BUT BETTER 

TO USE 5K POT. AND SET FOR 6 mA TOTAL CURRENT 



Fig. 6a. Schematic of the audio amplifier. 

The rf attenuator must have a usable range 
up to 150 MHz, I used a Jerrold Model A-72 
attenuator with the unit to provide up to 82 
dB of attenuation. First the signal generator 
must be calibrated against a known rf 
source, I found that my four crystals at 6 
MHz range varied no more than 10%. Next 
the crystal oscillator output must be set up 
for a reference output. Say you choose 70 
/iV t From the chart in Fig, 5 this cor- 
responds to —70 dBm, Now the rf attenu- 
ator can be put in series with the output and 
set for any value desired. For example, the 




Rear view of the unit showing circuit hoard 
placement. The audio amp is mounted along the 
top at the left with the crystal calibrator next to it 
at the right. The crystal oscillator circuit board is 
vertical next to the right wall of the cabinet. The 
power supply is tucked between the transformer 
and speaker. Note the subchassis used for mount- 
ing the vernier oscillator capacitor and crystal 
sockets. 




Fig. 6b- Full size audio amplifier P.C. hoard. 

crystal oscillator is set up for 70 juV, the 
attenuator is set for 31 dB. From the chart 
70 fxV corresponds to —70 dBm, If we add 

31 we have a signal of —101 dBm. This 
corresponds to 2 m v > We could use dBw 
instead of dBm and get the same results. 
Note: dBm - is the power in dB relative to I 
milliwatt; dBw - is the power is dB relative 
to J watt. 

Summary 

I think you will find this test set very 
useful for servicing and checking both re- 
peaters and mobiles, ft may be desirable to 
install a nicad battery with charger so the 
unit becomes truly portable. I have used this 
test set on some of the commercial frequen- 
cies around 160 MHz with excellent results, 

, . .VE7ABK 

The P.C. boards are available from 
Camgard Supplies Ltd., 2055 Boundary Rd. t 
Vancouver, B.C. The three available are for 
the power supply, the crystal oscillator and 
an audio amplifier. Each board sells for 
$2.00. The crystal calibrator board sells for 
$4.25 from Perfection Electronic Products, 
404 E\ Harrison, Royal Oak ML The com- 
plete kit is S19.95. 



JANUARY 1973 



69 






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70 



73 MAGAZINE 



Guy Slaughter K9AZG 
753 W< Elizabeth Drive 
Crown Point IN 4630 7 



DX- MISSING 



MADE EASY 



Uinner of the most DX-missed award 

As honorary president and lifetime 
member of the International DX- 
Missers Club, I was recently asked to speak 
on the topic of Blowing Rare Ones by a local 
ham group, and my remarks drew so much 
comment that I decided to condense them 
into an article for 73. 

In this way, it is hoped some of the 
rewards of failing consistently to hook DX 
stations can be relayed to others of the 
amateur fraternity who covet the awards, 
certificates and sense of accomplishment 
that come to dedicated and skillful hams 
who sharpen their talents for chasing and 
missing. 

In all modesty and only to display my 
credentials as an authority on the subject, I 
cite my logs and my lack of QSL cards to 
prove 1 have accumulated over the years a 
total of 347 countries missed. 

Not only that, but on one memorable day 
last August I racked up a five-band missed- 
all-continents record within a three-hour 
period. 

And twice I have come within one blow 

of the real Hat Trick: missing all zones in a 
single operating stint. 

This, I certify, all has been done on a 
somewhat limited operating schedule, always 
as a single-operator activity using a multi- 
plier of zero. 

Now granted, anybody with talent, 
patience and a willingness to learn from past 
mistakes could have accomplished these 
goals with extreme QRP and a non-radiating 
antenna. 



But, in all cases, my own achievements 
have been racked up with reasonable power 
(a quarter-gallon) to a three-element yagi 
atop a 50 ft. tower, everything peaked for 
maximum yield, the rotator properly cali- 
brated, and the feedline hooked to the rig. 

That's where true skill shows up in 
results. 

1*11 touch on one more phase of my 
attainments to complete my showing of 
credentials and prove the rewards that flow 
from sharpening your DX-Missing skills be- 
fore getting into the hereVhow-you-too- 
can-learn-to-blow-them portion of this verbal 
seminar. 

The proof of the pudding, so far as my 
abilities in this difficult field are concerned, 
lies in the awards that have come to me as a 
consistent misser of rare and common DX. 

I am the holder of certificate number one 
from the How Come Nobody Can Hear You 
Even When the Band is Open? club of 
America. 

I have on my shack wall the first Out- 
standing Amateur award ever issued to any 
U.S. ham by the International Organization 
of Your Key Clicks are in There But Where's 
Your Signal? 

1 own the original, though chipped and 
fading, ham-of-the-year plaque for 1957 
from the A-2 Operator's Club bearing the 
inscription, '"For Outstanding Contributions 
to the State of the Art of using Tri-Bander 
Beams as True Non-Radiating Dummy 
Loads/' 

And I am expecting almost momentarily 
the ultimate star for my crown of achieve- 
ments, the gold-inlaid handkey screwed to 



JANUARY 1973 



71 



the rear end of a plywood cat, inscribed: 
"To K9AZG, The Only Active Ham in North 
America Who Missed San Felix Island, CE0, 
While Hanging in There Reasonably On- 
Frequency with Reasonable Power." 

Hunh? 

But enough about me. Now* about you! 

If you have any modicum of talent as a 
strike-out champion in the ball game of 
chasing DX, you can improve your latent 
skills by mastery of a few simple rules, 

1 . Always zero atop the biggest and best 
signal in any pileup when calling a new one 
you intend to miss. 

2. If and when that big signal hooks the 
DX, rezero atop the next loudest caller* 

3. When working sideband, set your VOX 
to trip the rig in at the fifth syllable and to 
drop out between words. 

4. When working CW, double or halve 
your speed to call slow DX operators with 
burp-gun rapidity and fast ones at five words 
per minute. 

5. Time your calls to double with the DX 
for at least a portion of each of his transmis- 
sions. 

6. On phone, call the DX with whatever 
accent he is using, exaggerating it as much as 
your talent at mimicry allows, and giggle a 
lot, 

7. On CW, set your bug or electronic 
keyer to produce dots and dashes of pre- 
cisely the same lengths, preferably two 
bauds each* 

8. Call a lot and listen little. 

Those, then, are the basic and cardinal 
rules to learn if you wish your career as a 
DX-misser to flourish. 

There are other tricks, but mainly they 
are variations or refinements of the essential 
eight which you can hear on the air any time 
the bands are open and so emulate for 
yourself. 

One final word, however. Since hams are 
gentlemen and gentlemanly, it is of course 
unthinkable that any true amateur would 
cheat to accomplish his desired goal of 
winning laurels as a DX-misser. 

But there are those short-cut artists — 
mainly pirates, bachelors and phone men - 
who do so, 

For their benefit, and for those who 
might be tempted to follow in their foot- 









pyr 



£■■ 




steps, the following ploys are considered 
unfair, unethical, uncouth and unscrupulous 
tactics, and any DX-misser caught or even 
suspected of employing them is auto- 
matically ineligible as an award winner. 
It is not cricket to: 

1. Call a DX station more than 50kHz off 
his frequency. 

2. Tune up the beam for maximum SWR, 
minimum gain or poorest front-to-back 
ratio. 

3. Key or modulate the buffer-driver 
without including the final or turning on the 
high voltage, 

4. Call everything off the back or side of 
the beam, 

5. Call sidebanders on AM or phone DX 
onCW. 

6. Detune the final from resonance or the 
antenna coupler for minimum energy trans- 
fer. 

7. Send a string of breaks without signing 
your call from time to time. 

But of course no right-minded ham would 
do any of these things, rumor to the 

contrary notwithstanding . . . would he? 

, , K9AZG 



72 



73 MAGAZINE 



Donald J. Marx W2ANT 

32 Farm Road 

St. James NY 11780 



INSTALLATI ON 
AND METHOD 




ING 



A 60 





his article presents a method of raising 
and lowering a 60 ft tower with a 21 ft 
Comm Products omnidirectional antenna on 
top* 

I would like to start out by giving a little 
background story, I am one of those 
chickens who think they can climb a tower 
untO I get up to the 20 ft level - then I get 
what is known as white knuckles. Not 
realizing this until after I purchased this 
free-standing 60 ft tower, I was faced with 
the task of tilting it over or getting a 
monkey every time I needed antenna work. 
The tower comes in 10 ft bolt-together 
sections, I acquired it from a local ham who 
had a full 20m beam on it completely 
unguyed for over seven years, which with- 
stood many a good storm. The tower is 
made by Jontz, which is advertised in all 
radio master catalogs, dating back at least to 
1965. I have the heavy duty model No. 500 
which 1 strongly advise for the service which 
is about to be described. 

1 contacted the Jontz Company in order 
to obtain a new base, as the original one 
stayed behind inside a block of concrete. 
During the conversation it was revealed that 
there is a tilt-over base available to tilt this 
monster if the proper rigging is used. Hence 
this article. 

Mounting Base 

First a hole was dug 3 feet deep by 3x4 
wide, A wooden frame was built with 2 x 4's 
level on top of the ground surrounding the 
hole. This results in a finished job above 
ground. This frame also helped to support 



OWER 




JANUARY 1973 



73 




the tilt-over base during 

concrete. 



the pouring of 



Rigging Pole 

The rigging pole is a permament 4 in. 
mast which is also embedded in the concrete 
base. We acquired three sections of 4 in. 
diameter 10 ft electric conduit with slightly 
damaged threads, After forcing on two 
couplings and welding, we had a ridged 30 ft 
rigging pole. We buried 3 ft in the concrete 
with 2 ft protruding out the bottom of the 
concrete into the dirt. This leaves 25 ft 
standing out of the ground. I believe 3 in. 
diameter pipe would do the job as well. The 
raising of this 30 ft pipe was a bit difficult 
until we had taken advantage of some trees, 
plus block and tackle. After raising it up and 
into the hole prior to pouring concrete, we 
used rope and ground stakes to guy the mast 
perfectly straight to insure its permanent 
position. After traeing up the mast and 
tilt-over base, we proceeded to pour a good 
concrete mix and allowed two days for it to 
set before proceeding. 

Rigging Pole Pulley 

This pulley is mounted on top of the 
rigging pole to enable a boat winch cable to 
be routed over the pole via the pulley and 
act as the pulling point to lower and raise 



the tower. A steel pulley of good construc- 
tion is important at this point. 1 used a steel 
belt pulley from an old 2 hp motor with a 1 
in. shaft diai eter. We had taken advantage 
of one good threaded end of the 4 in, 
conduit to mount this pulley assembly. 

Rigging Pole, Back Guys and Anchors 

The anchors are critical along with the 
guy cable in that if they pull out or the cable 
breaks, the tower w\l fall during raising and 
lowering (enough said), I used 8 ft mush- 
room anchors similar to the type the lighting 
company uses for pole guying, but I have to 
admit they are more than you need. I used 
two pieces of lighting company guy wire 
(3/8 in.) which w^s considered as scrap. This 
was all secured with two conventional bug 
nuts at each point of fastening. 

Boat Winch 

The theory applies here also; if the winch 
falls apart during lowering, "... down will 




74 



73 MAGAZINE 







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£1* MTlNNJV 



come tower, antenna and all." By canvassing 
boat yards I received a donation of a rusty 
boat winch about 3,000 lbs. capacity. After 

much wire brushing, a coat of paint and 
replacing the drum shaft with a 3/8 in. 
stainless steel bolt (stainless steel has a very 
high shearing point), I felt safe in proceeding 
to mount same to the rigging pole, again 
using stainless steel bolts 3/8 in. in diameter. 
I would like to point out that there are 
many low priced inadequate boat winches 
available with pressed tubing for the drum 
shafts, etc.; be cautious. The same applies to 
the winch cable — don't scrimp. A typical 

boat cable is not long enough, so 1 purchased 
a 75 ft cable designed to withstand this 
weight and pull (3/16 in galvanized 7x9 
stranded vinyl coated, 4200 lbs.). 

Tower Guys 

Even though this tower is self-supporting 
after being raised and found to be stable by 
a tower climber, I felt that my sleep was 
more important than proving a point, so I 
decided to put three guys on the very top. I 
used 3 ft antenna guy anchors and the same 
cable as described for the winch. Here a 
lighter gauge cable could be used. 

First Raising 

With three guys attached to the tower top 
lying on the ground and all bolts, bug nuts, 
etc, tightened, I very nervously grabbed the 
winch handle with two hands and started to 



TQWCA 

«j*S to 

3 A ANCHORS 




crank. Not realizing a ratio of 6 to 1, I was 
amazed that it took only minimum effort. 
As it started to raise higher, I used two 
hands just in case one decided to quit. With 
the ratio of the winch it took a while to go 
up; but indeed it went up and stood there 
like an 8 1 ft statue. I locked the winch and 
bolted the tilt base. The tower was then 
cautiously climbed with a belt (not by me) 
to test for stability, which was found to be 
exceptionally good. Of course the next step 
was to lower the tower. This worked equally 
as well as raising. As a matter of fact, the 
tower went up and down three times that 
day. The final raising was followed by 
securing the three guys to the anchors 
(again, peace of mind). 

Conclusion 

I would like to make it very clear that I 
am not a mechanical engineer, nor do I claim 
to guarantee this safe or foolproof, but it 
does work. All comments pro or con would 
be appreciated. 

I would like to thank Joe WB2QEB for 
his original ideas, i would also like to express 
my deep appreciation to Norm WA2JPZ for 
his muscle, brains, ingenuity and moral 
support. 

. . .W2ANT 



JANUARY 1973 



75 



David E. Snavely WBSEBC 
2610 Oak Cliff Lane 
Arlington TX 76012 



A MA 






JAPAN 



It was an article in a late 1971 issue of 
QST that encouraged me to investigate 

the system of ham licensing in Japan. This 
particular article said that there were over 
230,000 ham licenses there and that Japan 
would soon overtake the United States as 
the leader in licenses issued. Why, then, does 
the Radio Amateurs' Callback list only 
about 15,000 Japanese tickets? 

It's true, now there are almost as many 
operator licenses in Japan as in the States. 
But to understand this it is necessary to 
grasp the excellent system of ham licensing 
in Japan, The development of this system is 
a beautiful story of cooperation between a 
strong, national radio society and 
government. This has resulted in 4 classes of 
tickets (see Table for description). 

According to information supplied by the 
Japan Amateur Radio League, ("Data on 
Amateur Radio in Japan/ 1 JARL, Tokyo) 
hams there got back into active operation in 



1952 (following, of course, World War II). 
There was a slow increase in the number of 
licenses until 1958. in this year, two new 
classes of operator license were introduced 
to supplement the older, general-privilege 
type First and Second Classes. These two 
new licenses allowed the holder to operate 
with a power under ten watts, and on all 
bands except 14 MHz, One was a Telephone 
Class (voice only, no code), and one was a 
Telegraph Class (code only). 

The advantage of these tickets is the fact 
that they are very simple to obtain. To get a 
First or Second Class operator license, a 
prospective amateur must be examined by 
the State at a selected examining point. 
Unfortunately, these exams are held only 
twice per year. The Japanese Ministry of 
Posts and Telecommunications (comparable 
to FCC) has, however, sanctioned JARL to 
conduct radio training courses for the Tele- 
phone and Telegraph tickets. By completing 



JANUARY 1973 



77 



— — 



OPERATOR 
CLASS 

First Class 



DESCRIPTION OF JAPANESE AMATEUR LICENSES 



SCOPE 



Second 

Class 



Telegraph 
Class 



Telephone 
Class 



Service operation and 
technical operation of 
radio equipments of 
amateur radio station, 
500W max. antenna 
power. 

Service operation and 
technical operation of 
radio equipments of 
amateur radio station. 
100W max. antenna 
power. 

Service operation and 
technical operation of 
radio telegraph of ama- 
teur radio station using 
frequencies above 21 
MHz, or below 8 MHz. 
10W max. antenna 
power. 

Service operation and 
technical operation of 
radio telephone of ham 
radio station using fre- 
quencies above 21 
MHz, or below 8 MHz; 
10W max. antenna 
power. 



No. of LICENSES 
(1971) 

2,998 



12,237 



21,253 



232,579 



TOTAL 269,067 



one of these courses, a student need only 
apply to the government for his ticket; no 
exam is necessary. 

These courses are held all over Japan. In 
1970, 559 such courses were offered and 
31,511 new operators were graduated. The 
students are taught theory and then send for 
their ticket, bypassing the painstaking wait 
for examination. 

In Japan, operator licenses are obtained 
first, and then an operator may apply for a 
station license. All stations must be ap- 
proved by a government inspector. The 
League is, however, authorized to certify 
station equipment (so long as its power is 
under ten watts), thus eliminating the need 
for state inspection, and most certainly a 
painstaking wait. 

Perhaps one of the major flaws of our 
own licensing system is the long waiting 
period involved. How often have you heard, 
*T would like to get a ticket but it takes 
forever and I just don't have the time?'' With 
these government sanctioned courses, the 
time is quickly reduced and the road is less 
rocky. 



The Telephone license is not a "CB" type 
ticket, either. People going through the 
JARL courses are taught radio theory and 
operating practice; they don't just buy their 
way in. Since this ticket requires no code 
exam, operators who might not wish to use 
code in their operation need not go through 
the pains of learning it. Again, the code may 
be stunting our own ham growth. 

Price tags are much lower in Japan, 
ranging from 504 (U.S.) for the ten watt 
operator tickets to $4.20 for a 500 watt 
station license. Here it may be noted that 
the maximum antenna power allowed for a 
station with a First Class operator is 500 
watts. 

The rapid growth of ham radio in Japan 
can be credited to an excellent, well organ- 
ized national society and a willing govern- 
ment. Hopefully, our own system could 
benefit from the Japanese ways and grow 
more quickly, too. 

The author is indebted to the Japan 
Amateur Radio League for their aid in 
supplying information. 

. . WB5EBC 



78 



73 MAGAZINE 



Bill Hoisington K1CLL 
Farover Farm 
Peterborough NH 03458 



A SIX METER CONVERTER 



USING 




INTERNATIONA 

he International Crystal Manufacturing 
Co. is to be congratulated on putting 
out a series of four little 1V4" X IW* kits 
with printed circuit boards and all the 
components needed to make up an excellent 
six meter converter for a total of onlv 
$17,40, including the transistors and the 
local oscillator crystal. 

Included are two rf stages, a mixer, and a 
crystal-controlled oscillator, each only 1 VS" 
X lYi" and 1-1/8" high. These are complete 
down to the last detail of plug-on connec- 
tors; they are furnished and each one of 
them works like a charm* You can assemble 
and solder any of them in less than an hour 
and if you pay attention to the precise 
instructions they work immediately. 

You should hear the stations piling in on 
the completed converter! Even though 1 am 
over 50 miles away from the nearest metro- 
politan area, I counted over one dozen 
stations talking busily one night as I tuned 
over the band, which was just as QRM-tree 
as I could wish. 

I'm going to assemble these kits, along 
with the International oscillator into a com- 
plete mobile and battery-portable station. 





KITS 



Fig. 1 Schematic of the SAX* 1 rf am^^ifier. 



These kits, the two SAX-1 rf amplifiers, 
the MXX-1 mixer, and the OX oscillator, 
mounted together in a minibox give you a 
high-sensitivity six meter converter to put in 
front of your present receiver. 

Don't forget that you're not limited to 
six. You can order kits and coils for any 
band between 2.3 and 170 MHz; quite a 
range. In fact, Im building a second one for 
two meters to go into a mobile-battery 

portable station. 

Pm really getting to like these little 

boards. They do everything that's claimed 
for them, and look at the prices! A crystal 
oscillator with the transistor sells, at this 
writing, for only $2,95, and every last little 
bolt, nut, and resistor is in that package. 
You do have to order the crystal separately, 
but at that price you don't care too much. 

The rf Stage 

The International SAX-1 kit is a small 
signal rf amplifier, with the *LO" kit from 
3—20 MHz and the "HI" kit carrying on up 
to 150 MHz. It is fine for six meters. The 
schematic is shown in Fig. L 

The SAX-1 rf stage went together easily 
enough; this time I soldered those staked 
pins right away. When the time comes to test 
it, one way is through the mixer, so I tackled 
that kit next. I advise doing the oscillator kit 
at the same time, then you will have the 
whole six meter converter to check out. 

However, I also tried the SAX-1 kit on 
the tuned diode receiver for use as an rf 
amplifier by itself and it showed plenty of 
gain on six. This gain varied a little with 
collector tuning, as expected , different 
lengths of cable used between the rf and 
mixer stage, or in this test case, to the diode 
receiver, making a slight increase. 



JANUARY 1973 



79 



With different voltages and cable lengths I 
was able to get as much as 40 times gain in 
power, hut i didn't need this much. The 
noise figure (good in my test) can be set by a 
nominal 10 dB in the rf stage, which you 
will get in any case. 

The unit handles perfectly and has shown 
no oscillation at any time. Of course, when I 
start putting these boards into an enclosure 
to make a compact front-end converter, 
some shielding may be needed. 

The Mixer 

Reading everything in the instruction 
sheet and checking out the parts, the printed 
board, and the connections in and out of the 
board for the rf, the oscillator injection, the 
dc inputs, and the i-f output, resulted in a 
good assembly and soldering job in a little 
over an hour. Like all these kits so far, the 
mixer worked right away. Figure 2 shows 
the mixer schematic. 

Before I could test the mixer plank I 
needed another oscillator on 22 MHz to beat 
with the 50 coming in, to give me an i-f of 
28 MHz. It happened that when I started 
using converters on six and two, my best 
receiver had a good 10 meter section in it, so 
most of my converters run with an i-f output 
of 28 MHz, 

In case you wish to operate with a 
different i-f you can simply order another 
crystal with your mixer-oscillator kits since 
the mixer outputs are broad-band. I put in a 
coil, as shown in one of the possible output 
circuits in the instruction sheet, since I am 




■K- 



CRYSTAL 
SOCKET 

m 




<+<voc 



-6V0C 



U QQ\ 

\{ <** 



GNC 



Fig, 2. Schematic of the MXX-1 mixer, Don't 
forget to use a ,001 IJF between the output and 
your receiver. 



Fig. 3. Schematic of the OX oscillator 

partial to tuned mixer outputs. It brought 
the mixer gain up quite well. 

The oscillator is next. Check the section 
after that for the mixers tuned circuit 
output. 

The 22 MHz Oscillator 

The schematic is shown in Fig. 3. 

I was getting to be an ^expert" now with 
International kits. Everything checked out 
fine, and this one went together as though 
"factory wired and tested/' I got output on 
22 MHz as soon as I threw the battery 
switch. I peaked up the coil correctly with 
the threaded core slug, which I inserted 
carefully; it works very tight. This is fine for 
holding the tuning while mobile, but take 
the precaution of working the slug back and 
forth while youYe inserting it, the same as 
with any tapping operation. 

All you have left to go for the front end 
is to connect everything up, watch out for 
feedback (I didn't find any) through the 
battery wires back to the input section, and 
build the tifneablt i f to go with it. I checked 
it out with my solid state Ameco R5 receiver 
as a ti neable i-f strip. 

T b . whole converter can be tested out for 
28 MHz output with a tuned diode receiver 
following it for a second method of check- 
mg. 

Going directly into a sharp-tuning ten 
meter receiver can be done, but requires care 
in lining up the converter. After all, it's nice 
to know that the front end does put out a 
good 28-30 MHz signal you can see on a 
meter even before you connect the receiver 
to it. 

Tuned Mixer Output Circuit 

On page 3 of the mixer instruction sheet 
are shown several block diagrams featuring 



80 



73 MAGAZINE 



r 


3A> 




SAJH-l 




UJXEH 




3AMMJ 

TLWED 
CIRCUIT 


INPUT 






UKX 1 




























SMHt 

0* 





?B MM; 

output 



Fig. 4. Block diagram of the six meter converter. 

assemblies of mixer and oscillator; and last, 
the rf stage, mixer, oscillator and receiver. 
My advice is to use the last mentioned 
assembly plus the mixer output tuned cir- 
cuit. This really peaks things up and drops i-f 
leakage almost out of sight. 1-f leakage 
occurs when you pick up an unwanted signal 
directly on the i-f frequency with your 
receiver. The importance of getting rid of i-f 
leakage is very great. Two things will do this 
for you. First, plenty of signal from the 
converter, which simply overrides the leak- 
age signals; secondly, good shielding and 
inter-unit grounds. Figure 4 shows the com- 
plete converter assembly used here. 

Your ten meter receiver is now loaded 
with 28 MHz noise-plus signal. That's good 
because it swamps out most of the i-f 
leakage . 

The tuned mixer output circuit deserves a 
word or two more from the point of view of 
bandwidth adjustment. The signal power it 
puts into the receiver being used has already 
been mentioned, and the frequency band 
over which it does this can be adjusted in 
width as follows. Figure 5 shows the circuit 
of this little Speaker-upper." Fve always 
tuned my mixer outputs; a comparison with 
tuning and without on this converter shows 
why. Use good shielding and good cables 
throughout to keep the i-f leakage down. 

TUNE TO 28 MHi 



FROM 

MIXER 

OUTPUT 




TO RCVR 
INPUT 



Fig, 5. Tuned circuit used with mixer output stage. 
LI, IT no. 18, 5/8 in. dia. t 4 TPI; Tap at 3 turns 
from ground; Tap 2 at 1 turn from ground; CI, 
ARCO 426, 35 to 275 pF, 



the EL SOCKET 



-* 



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L**' 



V 



**< 






I-** 



1**1 



^ * 












^> 






-- 



L^*f 



1* 



r ft»«H 






r 



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m '* 



mm 



S/*# 



* *■ 






** 



;***. 



Test new circuit ideas 

la Wa CirCUItS . a a 

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Telephone: 203/735-8774 



JANUARY 1973 



81 



Tap 1 adjusts the impedance match of the 
mixer collector on 28 MHz to LI and tap 2 
adjusts the output loading, I used a tap at 3 
turns for the collector and a tap at one turn 
for the receiver. This letter may vary with 
the receiver used. 

Second rf Stage 

This one really topped off the whole 
enterprise. It is my opinion (subject to 
further checking) that 99 ? of the possible 
birdies, the spurious harmonic detection, 
and the i-f leakage are eliminated with use of 
this stage. The increased six meter signals 
now swamp out any unwanted outof-band 
signals, 

One of these days I*m really going to lash 
up a "TRF* receiver! Maybe five or six rf 
stages. Actually two good ones are probably 
all you need, because by then you have 
practically eliminated problems of gain , sen- 
sitivity, noise j image, and other spurious 
reception from your design, leaving only the 
questions of frequency tuning, dial calibra- 
tion, and selectivity for your i-f section. 
These are generally taken care of in your 

communications receiver. 
Frequency Correspondence 

This worked out very well using one of 
the OX oscillator kits and plugging in 50, 
50-5, 51, and 52 MHz crystals that just 
happened to be lying around the shack, I 
checked on the receiver, and sure enough, at 
28, 28.5, 29, and 30 MHz there were the 
signals, converted down from six meters. 
This of course is the whole idea to get from 
six meters down to where you can tune it in 
on a reasonable cost receiver, on ten meters, 
for example. However, it is nice to see it 
spread out right in front of you, and, too, 
this gives you some idea of the in-band 
frequencies you tune in with your receiver. 
As I type, I can hear many signals on six, 
including some SSB on the low end of the 
band. 

When the two meter converter is 
assembled and wired I'll need a four MHz 
band on the receiver, but that's where an 
all-frequency receiver, 0.5 to 54 MHz comes 
in handy. If you have an amateur band-only 
job you can use different crystals in the 
converter to tune over a wider band than is 
available in such u rig. 



Harmonic Detection 

This is a very nasty thing to enounter. It 
has discouraged many an amateur builder as 
well as old pros. You're tuning nicely over 
the band when suddenly you come upon the 
most awful racket you've ever heard. One of 
your oscillator harmonics, times two, three, 
or four, from 22 MHz up to 44, 66, and 84 
and even higher landed on a TV or FM 
station. One of those t4 fifty thousand watts 
by Authorization of the FCCs jobs." You're 
using a narrow band AM dectector and these 
FM signals do not sound nice at all. 

They also come in loud on a few inches 
of wire or components exposed on the 
bench. The answer is shielding and more rf 
stages, luckily enough the same cure used for 
i-f leakage. 

Listening on Six With a Complete Converter 

I braced up a wide-spaced four ele- 
ment beam only about three feet over the 
ridge pole and immediately was listening to 
several lads chatting away. This was noon 
and mind you, a Wednesday. Rotating the 
beam and hitting myself on the head for 
neglecting this band for several years, I heard 
over a dozen stations in the eastern New 
England area some 75 miles south of 
Peterborough NH, A 90% QRM-free band 
with MHz width! 

My main lab receiver is an all solid state 
job tuning from 0.5 — 54 MHz, as men* 
tioned, for only $89, the Ameco R5. It is 
doing a good job with this International 
converter just finished, considering the com- 
promises that must be made in the receiver 
in order to tune such a range. As well as 
listening to the first six amateur bands while 
I write and work it is extremely useful for 
various things in the lab, such as listening to 
oscillators you may be building anywhere up 
to and including 54 MHz. And now of 
course I'm using it as a tuneable i-f for the 
International converter on six, and soon for 
two also. 

At 7:30 to 8 A.M. several mobiles were 
coming in from Sudbury, Wayland and 
Framingham, MA, to name a few towns 
heard from 50 airline miles plus. These 
signals come right over Temple Mountain, a 
2000 foot ridge in my backyard. 

. . .K1CLL 



82 



73 MAGAZINE 



J. D. Lamonica XYL W7DXX/1 



THEW 



HE HAM 



AND THE OTHER WOMAN 



The wife was happy and so was the groom 

At least 'til the end of the honeymoon. 

Then, alas and alack! Oh, pity the wife 

She discovered another in her husband s life. 

When home from work he'd rush through 

the house 

To hear the words from her squawking 

mouth. 

Alone in his shack with her he 11 sit 

As long as his sleepy eyes will permit. 

His meals are prepared on a TV tray 



Which the wife sets down, then tiptoes 

away. 

She must not disturb with whisper or sigh 

The other woman and her avid guy. 

From family gatherings hell usually abstain 

With explanations weak and lame. 

Friends and relatives feel put down 

When he retreats to his sacred ground. 

Many nights on bended knee 

The wife thanks heaven for color TV. 

Her husband has said: "What I am f I am " 

And heaven help her - the nut is a ham. 






My husband one day showed me an 
article in 73 that was reprinted from 

an Ann Landers column. A wife had written 
to complain about her husband's interest in 
ham radio, Ann Landers responded with 
something to the effect that a woman who 
could not get her man away from a piece of 
machinery did not have much imagination, 
Have I got news for her. Racquel Welch in 
the nude wouldn't interest my husband 
when he is engrossed in his conversations 
with those people who have only call letters 
and no faces. 

Most wives of hams probably fight the 
eternal triangle of husband, wife, and the 
radio, but my husband happens to operate a 
remote on top of a 9000 foot mountain. 
Whenever he has to check his radio it takes 
all day, and I am required to sit at home so I 
can give him test counts. Some of my most 
frustrating moments have been, when in the 



middle of a project 1 could not put down, 
like changing a baby's diaper, I'd hear a 
voice saying "Honey, if you copy me now 
give me a ten count." To ignore him would 
only mean he'd think he wasn't getting 
through. That would mean he'd spend more 
time on the mountain in 15 feet of snow 
working on something he didn't really have 
to. Frankly, I'm beginning to live with the 
idea that fci Big Brother" is watching me. My 
husband's control unit for the remote fits 
neatly in a closet in our master bedroom. 
How many other wives have been awakened 
at 3:00 in the morning by a strange voice 
asking "Anybody copy through the W7DXX 
repeater?" A couple of days ago I found him 
staring at a map of the world. "What are you 
looking for?:: I asked. "Oh," he said, "I was 
just refreshing my memory on the exact 
height and location on ML Everest. " . .... I 
fainted* 

Jacqueline D. Lamonica 



JANUARY 1973 



83 



mm 




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84 



73 MAGAZINE 



M, Mann C8ABR 
71 Queens Road 
Tewkesbury, Glos* 
GL20 5EL, England 



TUNABLE 



AUDIO 



LTER 



Like to build an audio filter for your 
| receiver that will give you a 
substantial reduction in heterodyne and 
noise interference? The unit is intended to 
be connected between the speaker output 
of a receiver and the operator headphones, 
the insertion loss of the filter being enough 
to drop the normal speaker output power 
to a comfortable headphone level. The 
filter consists of two sections directly 
connected together as shown in Fig. I. The 
first is a 500—2000 Hz bandpass filter to 
reduce the audio bandwidth to that 
required for human speech, and its 
response is shown in Fig, 2 A* The second 



FILTER 






BAftOFASS REJECTION 

NOTCH 



Fig. 1. Block diagram of filter. 

section is a very effective tunable notch 
filter that will tune out any unwanted 
continuous tone such as a heterodyne. It 
tunes from 350 to 6000 Hz and its 
response is shown in Fig. 2B. 

Figure 2C shows the overall response of 
the two sections. The notch can of course 
be moved in or ouf of the passband. The 
resulting hole in the audio response has 
little effect on speech, and if no 
heterodyne is present, it can be usefully 



adjusted to produce some improvement on 
certain signals. 

Details 

Figure 3 shows the complete circuit 
diagram. The bandpass filter is a 
straightforward type consisting of 
constant-k low-pass pi and high-pass tee 
sections. This arrangement uses the least 
number of inductors and also produces 
steadily increasing attenuation outside the 
passband. The tunable notch circuit uses a 
Wien bridge arrangement. Figure 4A 
illustrates the basic operation of this 
circuit. At a frequency given by / = 
1/27TCR the impedance of the parallel CR 
combination, let this be Z, is half that of 
the series CR combination, as shown in 
Fig. 4B. Since the other resistors are in the 
same ratio, the bridge is balanced and no 
signals at this frequency are 'heard in the 
headphones. At all other frequencies the 
bridge is unbalanced and signals are heard. 
By making resistors R ganged and variable, 
the bridge can be tuned to reject any 
desired frequency. 

The circuit diagram shows a 1 k£2 





Fig. 2. Bandpass response of filter sections. 



JANUARY 1973 



85 




_^-l 



Fig, 3. Filter circuit diagram. 



potentiometer. This is a "fine" balance 
control to allow for differences in the 
values of the 0.047 juF capacitors and 
errors in the tracking of the ganged 
potentiometer. In practice, this control 
needs little adjustment. The output goes 
via resistors and a transformer to the 
headphones. Two resistors are used to 
balance the winding capacitance of the 
transformer to ground, which would 
otherwise lessen the sharpness of the 
rejection notch. 

Construction and Operation 

The construction is quite 
straightforward except that because of the 
sharp notch an epicyclic drive to the 
ganged potentiometer is essential. The 1 
kO potentiometer just needs a small knob. 
The stray capacitance around the Wien 
bridge components should be reduced as 
much as possible and the wiring to the 33 
k£2 resistors kept short. The whole unit can 
be mounted in a minibox. 

Before finally screwing the lid down, 
check that the headphone level is 
satisfactory. If not, change the value of the 
33 kfl resistors accordingly, keeping them 
both the same. To get some idea of the 

effectiveness of this filter, tune in an AM 

x 
o 



station with the receiver bfo on; then 
carefully adjust both the controls until the 
heterodyne disappears. 




Fig* 4. A&B. Wien bridge arrangement as used in 
fitter. 



Alternatives 

The classic tunable rejection notch 
circuit is the parallel tee. However, 
although it does not need a balancing 
transformer, it does need a three-ganged 
potentiometer, and its notch is not quite as 
sharp as the Wien bridge arrangement. 
Therefore, I considered the Wien bridge 
arrangement to be a more practical 
solution. 

An alternative inductorless bandpass 
filter is shown in Fig. 5. This had a 
bandwidth of 200-5000 Hz, but the shape 
is not quite as ideal. It is quite effective, 
though; and if used, it should be inserted at 
points X in the circuit of Fig. 3, 

X 

9 



100 a. 



IOO jv 



100 A 



IOO/L 



iH7|ir 



0*? yF 



IOOji 



o.ii jjF 



0.68 pF 





Oti JJF 



0.6* J|F 



0#7 jiF sT^Mr,,? ^,0*7^ 



I0K 



K>K 



»OK 



0MB *iF 

-3 




K>K 



KMt 



Fig. 5. Alternate bandpass filter. 



. . .G8ABR 



86 



73 MAGAZINE 



r 



^ 

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Any color filter can be used. 



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here is a misconception floating around 
that homebrew equipment must look 
that way. To me this is a lot of baloney. I 
say that homebrew equipment can look as 
good as you want it to, and Pm sure many 
builders will go along with me on this. A 
little time and effort in the construction of 
homebrew gear can and does pay great 
dividends in the amount of satisfaction 
received in operating a rig you built from 
scratch. Some fellows have never realized 
this pleasure, and in a way it*s a pity. (I had 
better get off my soapbox and get down to 
the real purpose of this article.) 

In the following pages you will read 
about a linear amplifier that may convert 
you from an appliance operator to an avid 
home brewer. 11! try to present the material 
in such a way as to give the inexperienced 
builder a chance to become experienced, and 
the experienced builder the opportunity to 
become a even more competent. 

The amplifier is basic and complete, I will 
go over each section and cover it to the best 
of my ability. The general circuitry of the 
amplifier is pretty standard and science will 
not be shaken by any new circuit dis- 



coveries. However, the purpose of the article 

is to present the standard circuit in such a 

way that we can approach our junk boxes 

instead of our pocketbooks. By the way, I 

might mention that the linear cost me $50 

complete. This figures out to about 54 a 

watt. Not a bad investment. Although I did 

quite a bit of scrounging from my junk box 

and that of my friends, I am certain that the 

average builder can come pretty close to my 

price if he has a reasonble junk box or 

friends with junk boxes, or both. Preferably 

both. 

I hope I have enough of you fired up 

now, so let's get down to business. 
General Layout 

Before I go on, I should explain that the 
linear uses four 81 lA's in grounded grid and 
runs at an input of about IOO0W PEP. The 
SllA's are a fairly common tube and no 
trouble should be encountered in locating a 
few. The linear is housed in a DX 100 
cabinet. This cabinet provides lots of room 
for the bigger surplus parts I used. The 
builder may want to cut down on the size 
for some reason, With a little planning in 
layout, this can be done. 



JANUARY 1973 



89 



DETAILED DRAwtNG OF Dl AND 02 




-'."..' — * — *^Ai ■ * */& * * *W^ — • — 'V^V — ' 



AESiSTORS 4T0K 1/2 WATT 
CAPACITORS 0047 MFD 1000 V CERAMIC 
DIODES 1000 Piv I AMP 

Di IS IDENTICAL TO 02 

Fig. I. Series diode bank used in the power supply. 

The first rule in the homebrewing game is 
to scrounge a lot. I can't overemphasize this 
fact. Ask around for a part you need* More 
times than none you'll find a fellow glad to 
give away a piece of junk that you are 
tickled pink to get your hands on. One 
example of this is the cabinet and chassis I 
used in the linear. They were both ideal for 
my purpose and neither cost me a cent. 
These two pieces of equipment obtained free 
offer a great savings on the total cost of the 
linear. 

The Power Supply 

It is good practice when building to 
design each section with a higher breakdown 
rating than will ever be encountered through 
normal use. By designing something with 
this in mind, you can be sure that the circuit 
will probably outlive you. 

The diode bank that I used is shown in 
Fig. I. The bank is good for 5000V at 1 A. 
Some rating, isn't it? The following is an 
explanation of why and how I made the 
diode bank so husky. First, I used a voltage 
doubling circuit. This meant I needed two 
diodes at the very least. Because I wanted a 
rugged diode bank, I used five 1000V 1A 
diodes in series to form one bank of the 
doubling circuit. I did the same for the other 
bank and wound up with a board containing 
10 diodes, 10 resistors, and 10 capacitors. 
The resistors and capacitors are shunted 
across the diode to prevent harmful spikes 
that could zap a diode. Some of you may be 
dubious about using 10 high voltage diodes. 
Have no fear. The diodes are relatively 
inexpensive and can be purchased cheaply 
from Poly Paks. All components are mount- 
ed on a phenolic terminal board. 

Now that we understand the construction 
of the diode bank, let's backtrack a little to 



the ac end of the power supply. The ac cord 
runs into a preventive device called a brute 
force filter. The purpose of the filter is to 
block any rf from backing up through the ac 
power lines. This is an inexpensive pre- 
caution against interference, the number one 
enemy of ham radio. The coils are made out 

of #16 enamled wire and wound on a round 
form about l A in* in diamater. They are close 

wound for about Wi in. Two of these coils 

are wound and placed between two terminal 

strips. The coils are placed in the ac line and 

any rf is bypassed to ground through the 

four capacitors. The number of turns of the 

coil or its diameter are not critical, this 

flexibility of the construction adds to the 

filter's simplicity. 

From the filter, the ac passes through a 
fuse and a switch on its way to the trans- 
formers. I used two different transformers 
for the foLl owing reason: Each filament of 
the 81 IAS draws 4 A. Since we are using 
four of them, we have a total current drain 
of I6A. Since most power transformers do 
not carry that heavy a 6V winding, I 
scrounged up a surplus transformer rated at 
20A. Not only was it perfect for the 81 lA*s, 
but it was free (another example of 
scrounging). The other transformer I used 
was an old TV-type that can be dug up by 
anyone taking the time. 

As stated before, the power is routed 
through a switch. I used two switches, one 
for the filaments and the fan, the other for 
high voltage. The ac switch allows current to 
flow through the primary of the filament 
transformer while none flows through the 
high voltage transformer. By throwing the 
high voltage switch, the current is routed 
through the primary of the high voltage 
transformer. This is a safe way to turn the 
B+ on and off while the filaments stay lit. As 
an added precaution, it can be seen in the 
schematic that the high voltage will not be 
turned on unless the filament switch is 
thrown. This prevents high voltage from 
being applied to a cold tube. 

To get the high voltage I needed out of a 
900V transformer meant I had to use a 

■ 

circuit that boosted the voltage up. This is 
why 1 used a full-wave voltage doubler. I 
have already explained the diode bank, so 



90 



73 MAGAZINE 



iNPUTf**) 



MOWTQR 




* -SEE TEXT 



AUXILARY 

METER 
SWITCH 



Fig, 2. Schematic diagram of the linear amplifier and power supply. 



now I will explain the filtering action. The 

outout of the diode bank is fed to two 

surplus oil capacitors. These are located on 

the extreme right end of the chassis. These 

capacitors are rated at 1200V with 16 juF 

capacity. By placing the two capacitors in 

series I had a safe breakdown rating for the 

filter. 

The filtered no-load dc output of the 

supply is about 2200V T During operation the 

voltage drops down to about 1400V, The 

reason for this big drop is the size of the 

capacitors. If the builder wishes, higher 

capacity computer-grade capacitors could be 

installed and a little better regulation would 

be realized- I might mention that the oils 

have worked well for me and they should 

continue that way for a long time. 

It must be remembered that the ac lines 

in your circuit are going to carry the current 

of the entire unit. Use the proper wire. 

Don't try to get by with a smaller size; it will 

work for a while, but you want something 

that will work forever. Another word of 

caution — lethal voltages exist in your power 

supply. Use your God -given brains at all 

times. You wont be given a second chance. 



After you finish the power supply, you 
have almost half the linear done. Now you 
can move on to the rf circuits. 

The Input Circuit 

I'll begin the explanation of the input 
circuit with a description of the bifilar 
choke. The choke is wound on a ferrite core 
measuring about 5 l /i in. in length and about 
Yi in, in diameter. Although I feel that the 
choke is larger than would be needed, it 
works out well. You may want to refer to 
the September 1967 issue of 73 for a 
detailed description and explanation of de- 
signing bifilar chokes. This article will tell 
you how to figure what length of coil you 
will need. I suggest that it be read thorough- 
ly before the construction of the choke. The 
windings are made of #12 wire. Remember 
that the full 1,6 A in the filament line are 
flowing through this wire. All I can say is, 
the heavier the better. Two equal lcnghs of 
wire are cut and wound side by side around 
the ferrite. If you did a good job and used 
heavy enough wire, the windings will cling to 
the ferrite and you will have one solid unit 
that could be used in a battleship. 



JANUARY 1973 



91 






One last word on the choke. Don't bother 
buying one. You can do it for less than a 
dollar, and if you already have a ferrite core 
lying around, you can do it for nothing. 
Besides, it's fun. 

Looking at the schematic, you will see 

that I have a 150O 20W resistor shunted 

across the filament winding. You will also 

see that the tap is grounded. I did this 

because the transformer that I dug up did 
not have a centertap. So I figured the next 

best thing was to make my own. The 
grounded slider serves as a return point. 
Without it the linear will not function- 

You will notice on the schematic that the 
input first goes to a relay switch. The 
purpose of the relay is to enable the opera- 
tor to switch the linear in and out of the 
circuit. This device comes in handy, and I 
recommend that it be installed in this linear 
for reasons of convenience. The relay is 
activated by the high voltage switch. In this 
way, the operator can transmit with low 
power while the filaments are heating up and 
instantly have high power by flipping the 
high voltage switch. A word should be 
mentioned here about the relay itself. Since 
the relay (DPDT) will be on as long as the 
high voltage is on, you must use a continu- 
ous duty relay. The relay contacts must also 
be heavy duty. The relay I used cost me 
about $4.50 and had contacts rated at 12 A. 
Although I bought this relay new, you may 
be able to find one in your junk box and 
thus knock five bucks off the total cost of 
the linear. The operation of the relay is as 
follows: The input rf is fed to the middle 
arm of the relay. With the high voltage off, 
the power is fed directly to the output jack. 
When the relay is activated , the input rf is 
fed to the filaments and the output jack is 
connected to the linearis tank circuit. In- 
stant power. 

Although the grid circuit is technically 
not a part of the input circuit, I'll explain it 
here. Each grid lead is bypassed for rf by a 
.01 capacitor. The leads are also bound 
together at a central point and run to one 
screw terminal located on the rear of the 
linear. The other terminal is grounded. When 
in use, a jumper is connected between the 
two screws, thus grounding the grids, How- 



ever, when the linear is idling, -100V 

(available off the hack of most exciters) is 

fed to the grids, making them cut the tubes 

off. Thus during idling no great amount of 

current is being drawn by the tubes. The 

— 100V is usually controlled by a relay in the 

exciter and this relay automatically grounds 

the grids of the tubes during transmit. 
The Tubes 

As stated previously, the tubes used in 
this linear are 811AV The builder may 
choose to use a different type of tube that 
he has on hand. This is well and good 
providing he takes everything into considera- 
tion — such as the power supply, input 
circuits, and tank circuits. Since 1 was not 
certain as to whether or not I would ever 
change the type of tube used in the linear, I 
constructed the tube layout in a somewhat 
novel way. I took a 5 x 8 sheet of steel and 
mounted all four tubes symmetrically on it. 
I mounted the choke in the center of the 
four tubes, giving me one solid unit of four 
tubes. I then cut a 5 x 8 hole in the chassis 
and had a place to mount the tube plate. 
The tube plate lies flat against the chassis 
and it is barely noticeable that the tubes are 
mounted on the plate. The purpose of 
mounting the tubes in this manner is simple. 
Suppose I want to run two 572B 1 s instead of 
my SMA's. All 1 have to do is make a 
separate plate and pop it in the old hole. It 
makes for easy modification because the rest 
of the linear can remain the same. This little 
feature can prevent a great headache for the 
ham who likes to experiment with different 
tubes. The tubes are placed a reasonable 

distance apart, as common sense dictates. 
Although I could probably get away 

without cooling the tubes, I feel the little 

extra effort is worth the dollars saved in 

extra tube life. 1 used a cheap but effective 

ac fan for the cooling action. This fan is 

activated when the filaments are turned on. 

The fan, although small, circulates the air 

around the tubes just enough to prolong 

tube Ife* The fan is mounted on an angle and 

the main stream of air flows toward the 

center of the tubes. The fan is quiet and one 

must really listen for it in order to hear it. I 

paid a dolJar for the fan I used. There are 

many available on the surplus market for 

about that price. 



92 



73 MAGAZINE 



The leads from the plate caps are brought 
together at the top of the rf choke. This 
choke acts as a terminal point for the leads, 
The leads are covered with ferrite heads for 

the purpose of parasitic suppression. The 
beads provided me with better results than 
could be obtained with the old coil-resistor 
combination. The B+ line is bypassed for rl 
by a .001 3 KV ceramic capacitor which is 
mounted at the extreme bottom of the rf 
-choke. From here, I used Beldon #7766 high- 
voltage wire for the connection between the 

choke and the power supply. 
The Tank Circuit 

I incorporated a conventional PI network 
in the tank circuit. The B+ is blocked by a 
820 iiF 20 KV doorknob capacitor mounted 
just before the tuning capacitor. The value 
of this capacitor is not critical, but the 
voltage rating must be high. From this 
capacitor the rf is fed to the tuning capaci- 
tor. The capacitor I used was a Johnson 
154-2-98. The capacity of the unit is ap- 
proximately 350 pF, I obtained the capaci- 
tor surplus for about §5. Again if the builder 
can dig one up he can save himself another 
five bucks. The output capacitor was one I 
had found in the shack, and heaven knows 
where it came from* It is a three section job 
with all the sections paralleled to give me 
about 1000 pF of capacity. 

The 10 meter coil (Lj) is made from 
copper tubing. The coil consists of three 
turns wound on a 2 in. diameter form. The 
form is of course removed after the coil is 
wound, Li is made from two pieces of coil 
stock that I found in a friend's junk box. 
The coils were soldered together and a sheet 
of Lucite was cemented across the diameter 
to make a solid coil 3 in, long and about 4 
in. diameter. This Lucite provides extra 
support as well as a means of mounting the 
coil, The coil is mounted upright for the 
purpose of space saving. 

The rf switch must be heavy duty to 
withstand the rf voltages present in the tank 
circuit. The switch I used came out of an old 
army TU-7-B tuning unit. I purchased the 
unit for about $3. So far the only thing I 
used out of it is the switch, but there are 
many goodies inside worth saving. 

Many of you may be asking the natural 
question of where to tap the coil for each 



band. The answer is simple. Beg, borrow, or 
steal a grid dip meter with a reasonable 
accuracy. Start with 10 meters and work 
down. Adjust the input and output capaci- 
tors so that they are half meshed. Insert the 
grid dip coil into L] and tap down on the 
coil until a dip is noticed. You now have 10 
meters set. Now move to I 5 and so forth all 
the way to 160. The taps are brought out to 
the switch. It should be mentioned here that 
the GDO should be set to the middle of the 
band being tuned. 

Since the only effective way of knowing 
whether ox not you are flat topping is to 
see it on a scope, I incorporated a scope 
monitoring circuit. The circuit forms a capa- 
citance divider network to which the vertical 
deflection plates of an oscilloscope may be 
connected. By increasing the capacitance of 
the 20 pF variable, you effectively increase 
the level of signal going to the oscilloscope. 
The circuit is very handy for monitoring 
purposes. 

Metering 

In my linear I have one meter perform 
three different duties for me. It reads plate 
voltage, plate current and relative output. 
Looking at the schematic, you may wonder 
whv I used two meter switches. 1 had a small 
wafer switch available in my junk box. The 
switch contained four contacts. Since it was 
very possible with this switch to make 
contact with two points simultaneously, 1 
thought it necessary to space the current and 
voltage positions one contact apart. This left 
me no room for the relative output position. 
I then installed a toggle switch which either 
connects the meter to the regular meter 
switch or to the rf monitoring circuit, All 
this circuit does is sample a little rf by 
rectifying it and feeding it to the meter. The 
2K pot is used as a sensitivity control and is 
mounted on the front panel to the left of 
the meter. The circuit is useful during 
tuneup as an output indicator. 

A detailed explanation of how to deter- 
mine meter shunts and series resistances is 
given in most handbooks. They will provide 
you with all you need to know about meter 
circuits and should be consulted before any 
attempt is made to design your meter 
circuit. 



JANUARY 1973 



93 



™» 






The Final Touches 

Up to this point you've had it pretty 
easy. Whatever mistakes you made will not 
be noticed from the outside- Now you are 
faced with the tricky and delicate part. Your 
main objective is to make your homebrew 
equipment look professional. The outside of 
the linear is what is going to strike people's 
eyes. It is from appearance that most people 
draw opinions. 

Let's start with the basic front panel. 

First, remove the front panel so as to make 

it easier to work with. Give it a good 

washing and roughen the surface a little with 

fine sandpaper. The reason for roughing it is 

to give the paint a better surface to adhere 

to. Once you have it cleaned and roughened, 

apply the first coat of primer, I find that 
paint in a spray can allows for a neater job. 

Let the first coat dry thoroughly before 

applying the second coat. You can get by 

with two coats of primer, but if you want to 

play it safe, a third coat should be applied. 

After letting the undercoating dry for a day, 

apply the first coat of finish. The color is 

your own choice, but dark gray looks great. 

Allow it to dry and apply a few more coats. 

Now you have a clean, neat looking panel to 

work with. 

The next step is to apply the lettering for 

the equipment. Before you start lettering, 

make sure you know whai you want and 

where you want it. After the decals are dry, 

you have little chance to change your mind. 

Once you know where everything goes, your 

next step is to square things off. Draw guide 

lines in pencil to help get the decals straight. 

The lines can be easily rubbed off when the 

decals are dry. Don*t skip this step of 

squaring because you'll be sorry in the end. 

After you have the lines drawn you can 

begin setting the decals. Find the term you 

need and cut it out as close to the lettering 

as possible. After you have the decal on the 

panel, adjust it so the letters are even with 

the guide lines. Continue applying decals 

until finished. 

Stand back now and take a look at the 

panel, Youll be surprised at what a good job 

you have done. A word of advice: Practice 

before you perform the real McCoy. Practice 

will allow you to get the feeling of the 

decals. 



Operating 

Operating this linear can be considered a 
pleasure. If you have tuned other linears in 
your ham career you will have no trouble 
with this one. If this is your first linear, then 
the following explanation is for you. 

As I said before, the best device that can 
be used in the tuning of the linear is an 
oscilloscope. I won't go into a description of 
proper scope patterns, because this is a 
subject well covered in many handbooks. If 
you ean*t possibly obtain an oscilloscope, 
the next best device is to use common sense. 
Remember that by over-driving you are flat 
topping and creating a mess on our bands. 
The driving power for the four SllA's is 
about 100W, 1 drive my linear with an 
exciter that has an output of about 60W. I 
do not have to worry about over-driving, but 
the fellow with the higher power exciter 
does. If it is not possible to lower the power 
of your exciter to 100W, then it will be 
necessary to build an attenuator. These are 
also discussed in handbooks. Once you have 
the proper drive, you can tune up the linear 
just like you tuned up your first novice rig. 
Start with having the loading capacitor 
plates fully meshed. Now set your meter to 
read relative output and adjust the tuning 
capacitor for maximum output. Continue 
doing this until key down current is about 
600 mA. Remember not to keep the key 
down for too long a time. You can now 
switch to whatever mode suits you and have 
fun. Keep in mind that you should not 
exceed the dissipation rating of the tubes for 
too long a period. Treat them well and 
they'll reward you with long service. 

Conclusion 

Although I described the linear the way I 
built it, the industrious homebrewer can and 
should deviate from the circuit. At any rate, 
it can be seen that the linear can be built 
cheaply by using all the surplus parts you 
can get your hands on. Remember the name 
of the game — scrounge! 

I'll be happy to try to answer any 
questions on problems that pop up. If you 
have a problem, do not hesitate to contact 
me. 

. . WA9JMY 



94 



73 MAGAZINE 







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to most any part of the world. 

Address your orders to: 

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Farmingdale, N.Y. 1 1735 

Or — Phone your orders to 
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ORDER NOW! 
Or f ask for 

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Near City Hail (At Rockaway Ave.) 

BAr clay 7 7922 (5161872-9565 



96 



73 MAGAZINE 



CURREN 
HIGH 




NPN 



GA 
OWER 



N 



Ernie Johnston V/B4LVA 
P. O. Box 6 032 
Clemson University 
Clemson SC 2963 1 



S 



CON XSTRS 



While trying to design a high current 
power supply regulator, 1 found 
that suitable transistors available to the 
experimenter are few. And these transistors 
are not cheap; two of the three selected sold 
for more than S6. Current gain is definitely 
expensive in more ways than one, as this 
article exposes. 

But more important - of those available, 
the betas given were either in a range or as a 
typical value. The disparity was just too 
great. Having close at hand the facilities to 
measure accurately transistor current gain, I 
decided to measure them myself. This short 
article is a report of my findings. 

Beta is Not a Transistor "Constant" 

The results are presented in three forms: 
a table of beta values versus collector cur- 
rent, a picture of an actual curve trace, and 
the graph of the averaged beta values for 
each type of transistor versus collector cur 
rent. All were obtained (directly or indi- 
rectly) from a Tektronix 576 curve tracer 
and all illustrate the same main point; 



current gain decreases with increasing collec- 
tor current. 

Each representation does have its own 
specific advantage. The table will also give 
you some idea of the individual performance 
you can expect from these readily available 
transistors. The values given are for hf e ; Hf e 
would be larger as seen from the trace. fhf e 
is small signal current gain; Hf e is steady 
state current gain.) The curve trace shows 
you how I measured the beta and also allows 
you to determine the Hf e of SK3036 sample 
number 3. You could expect similar results 
with other transistors. The graph allows you 
to easily *see" the beta decrease (and how 
fast it decreases) as the collector current 
increases. I do not remember them ever 
mentioning in school that this would hap- 
pen! 

Conclusion 

The point to remember is this: the 
manufacturer's specifications are probably 
not applicable to your specific application. 
If possible, measure the parameters of your 

TABLE I 



Type 
Typical 

h fe 
Sample 

# 



HEP 704 
90 



BETA VERSUS COLLECTOR CURRENT 

SK3036 
100 



HEP S7000 
70 



1 



1 



3 



BETA (h fe ) 



15 Amps 4 



12 
10 

8 

7 

5 
3 

2 
1 
0.5 



8 
8 

10 

18 

40 
56 
90 

125 



2 

4 

6 

8 
12 
175 
25 
44 
70 
100 



8 
12 
14 
18 
21 
30 
45 
60 
85 
100 



12 
12 

14 
22 

20 

32.5 

55 

72 
105 
110 



9 

12 
14 

20 
25 
38 

60 

90 

125 

150 



11 


11 


9 


16 


14 


12 


20 


19 


20 


22.5 


22.5 


22 


25 


25 


22 


40 


35 


38 


55 


45 


50 


76 


58 


64 


115 


70 


78 


115 


93 


85 



JANUARY 1973 



97 



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Fig. J. Curve trace of RCA SK3036 transistor, 
sample #3. 

specific transistor; if not, use the most 
accurate data you can find- 
Obviously I could have extended my 
observations to other transistors and/or para- 
meters, This is indeed a worthwhile project- 
but I shall leave it to someone more industri- 
ous than [. 



LEGEND 

• SK3Q36 

O HEPS7000 
■ Htl J fW 




l c 1 Ampere* 1 

Fig. 2, Averaged beta values versus collector 
current for all 3 types of transistors. 

Acknowledgements 

I would like to thank the Department of 
Electrical and Computer Engineering, 
Clemson University, and in particular Dr. 
Lewis T. Fitch W4VRV, without whose help 
this project could not have been completed, 

. . .WB4LVA 

73 MAGAZINE 



IC 






USE WITI 



FOR 
SOLID 



Bill Hoisington KICLL 
Far Over Farm 
Peterborough NH 03458 



UNER 




VHF-UHF CONVERTERS 



This ten meter front end is highly 
suitable for use following crystal- 
controlled converters from six meters up to 
the 1296 MHz band, or higher. Its mixer 
output is on L65 MHz which places the 
image 3.3 MHz away, where it is many dB 
down, 

I will describe in detail the design 
method and circuit of a ten meter tuner 
using the Motorola HEP590 IC (integrated 
circuit) in the rf stage for high gain, high 
selectivity, and no feedback, Also used are 
the Miller 3-gang miniature variable capaci- 
tor and the Miller two-speed dial for proper 
coverage and easy tuning of the frequencies 
between 28 and 30 MHz. 

As we went through the rf stage, its use 
as a ten meter preamp by itself proved so 
excellent that this is also described as a 
bonus, and will prove to be a very useful 
piece of equipment at times. 

The use of the Motorola HEP590 IC 
results in high gain, high selectivity by 
virtue of the loose coupling between stages 
and tuning elements, and negligible feed- 
back in the rf stage* The reduction of 
image is thus considerably enhanced over 
that obtainable with a single transistor. 

As a ten meter preamp it adds an almost 
unbelievable pull-in power to a low cost or 
old receiver on ten. 

Available coil forms and coils are also 
used, which makes it easier getting com- 
ponents together for construction. 



Last but not least, the unit is packaged 
and ganged using a tracking method which 
does not consist of just connecting three 
coils to three sections of a gang capacitor 
and hoping for the best. With the method 
described you will get proper tracking and 
he sure of it. 



/7? 




.01 



I 



CABLE 
TO TEN 
/77 METER 
RECEIVER 



3-20 ©F 



+ *2V 



Fig. I. Pre~amplifier circuit diagram. If manual 
gain control is not desired, leave pin 5 on ground 

for maximum gain. Pretty simple, eh? 



The result is a battery-operated unit 
which in conjunction with an i-f system 
and a VHF or UHF converter, will furnish 
you with a mobile, portable, or emergency 
receiver having extreme selectivity and 
sensitivity, and cut you loose from depend- 
ence on your big 50 lb communication 
receiver and ae power. 



JANUARY 1973 



99 



£0 TO tO M Hi ATTENUATOR 



510 WAL 
GENERATOR 






l0O A 



RF 
HEP59Q 



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MIXER 

HEP 5S 
— I 






DIODE 
fN£93 



_*! 



*F — ^ 



-h( 



- : _ 




METER 



OSCtLLATOR 



M£P 53 



Z#63 TO 
51 63 MHi 



Fig* 2* Setup for coil alignment. 

The Motorola IC HEP590 as a ten meter 
preamp showed its high gain and practical- 
ly non-existent feedback. To be exact, even 
with high Q coils in the input and output 
circuits it has never oscillated even once in 
use so fax, from 135 kHz up to 50 MHz. 
Having battled with transistor feedback 
and neutralization for some years, this is 
really something. The 590 even handles 
better, tuning much like an old fashioned 
tube receiver input with symmetrical tun- 
ing instead of the unsymmetrical tuning as 
with the usual transistor rf stage without 
neutralization, 

The schematic of the preamp is shown 
in Fig. 1 , using the Miller subminiature 
coils in both input and output circuits. In 
this preamp the 9050 coils are left with 
t heir original windings and the extra wind- 
ings are added over them* For the 2 MHz 
bandspread tuning range of the complete 
front end using the three gang capacitor, 
the original 9050 windings are removed 
entirely as you will see in Fig. 3. 

This preamp, however, gave such a jolt 
to the present ten meter band on my lab 
receiver that I thought it best to describe it 
for you as a separate item. Once again, it 
features absence of feedback and has never 
oscillated once, in spite of all kinds of 
changes and tuning up for ganged opera- 
tion. 

Input to the 590 

See Fig, 2, block diagram, and Fig. 3, 
overall schematic. Table 1 gives you an idea 
of how to line up an input circuit for 



ganging use when a tuning range of only 2 
MHz is desired with a given capacitor that 
has a 5—20 pF capacitance range. The 
block diagram, Fig, 2, shows the coil test 
setup that enables you to do this with ease 
and confidence. 

As is the case with all the $30 signal 
generators that I've so far encountered, the 
attenuator on mine is nothing to write home 
about, and not enough shielding can be 
used for the money to do much good at 28 
MHz, but you can make up an external 
uncompensated attenuator that will do the 
trick for you. This little 1 00 to 1 box with 
its 10K in series and the 10012 in shunt is 
included in Fig, 2. Of course, attenuators 
of this sort are really perfect only at dc, 
but you'll be surprised at what it can do 
for you at 28 MHz just the same. It does 
give you relative power reduction and 
that's what you need here. With the signal 
generator gain about 3/4 on, plug the 
attenuator box into the "high" output jack 
and there will be a reasonable output from 
the HEP590 which will give about a volt or 
so of dc out of the diode, as in Figs. 2 and 
4. The test diode is clipped onto the mixer 
coil as shown in Fig. 4, and there is of 
course not much selectivity, but that's not 
what you're after here. You want relative 
gain as in Table 2 and relative tuning range 
with a section of the three-gang tuning 
capacitor, and this test circuit gives it to 
you in easy style. Be very sure that nothing 
is being overloaded as this will falsify your 
tests. The dc voltage out of the diode 
should rise to 4 or 5 V when pushing the 
input (do not do so) and drop to zero when 
the coils are detuned. Incidentally, if you 
plug an antenna into the input you can hear 
those Texas kilowatts on ten, and up on 



Turns on 


Relative 


Total Tuning 


L2, Fig. 3 


Volts out 


Capacitance 


8 


2.1 


30 


7 


2,1 


35 


6 


2.1 


40 


5 


2.1 


50 


4 


2,1 


70 


2 


2 


85 


Itt 


114 


110 


1 


N.G. 


N.G. 



Table 1. Relative gain vs turns on L2. 



100 



73 MAGAZINE 



+ I2V 



MILLER 
9054 

TUNE TO 
L7 Ll 1.65 MHz 




*>T0 HF 



CI, C2 t C3- MILLER 3 GANG, EACH SECTION 

5-20 pF 
C T -TUNING TRIMMERS, 5-80 pF 



Fig. 3. Ten meter tuner circuit diagram. The Miller 9050 and 9054 should be used it at all possible. 
They are ideally suited to this project because they are easy to modify and fully magnetically and 

electrostatically shielded. They are available through most large catalogs or directly from J.W> Miller 
Co., P.O. Box 5825, Compton CA 90224, For those who cannot get these coils f the 9050 varies from 
1.5 to 3.0 fJH and the 9054 ranges from 28.0 to 60 fJH, Also, the triple ganged capacitor used is 
non-critical. Do some experimenting until you get something with a maximum capacity of about 11 pF 
per section. 



the ] I meter broadcast band in the morn- 
ing South Africa, London and others boom 
in very loud. 

Note that this is without any i-f at all so 
far. 

Meanwhile, back at Table 2, referring to 
Fig. 3, you can see at a glance the relation 
between the number of turns on L4 and 
the tuning range. This subject is of great 
importance in making a ganged job and is 
taken up in further detail in the next 
section. Proper tuning is always important 
for selectivity, which also reduces image, 
and especially for a three-gang capacitor 
tracking unit, which is difficult enough 
without putting odd bends in the tracking 
curves. If you think it's a lot of work to 
take a three-winding coil in and out of a 
circuit 8 times to add or subtract one turn 
each time, you're so right! But it's worth 



it. Tve left the whole front end alone near 
29 MHz for several days now and just tune 
over a 100 kHz or so with the lab receiver 
on 1.65 MHz as an i-f and G's, W7's, ZS 
and VC stations have been on the air most 
of the time. It's really stable and good, 
even in breadboard form. 

Table 1 shows the relation between the 
number of turns and the gain, or conver- 
sion efficiency of the converter. Only when 
you cut down to less than 4 turns does the 
gain begin to drop. This allows you to pick 
the tuning range you want, still using the 5 
to 20 pF section of the Miller three-gang 
job as is, 

2 MHz Dial Spread 

This ten meter front end, while very 
interesting on ten. is primarily designed for 
use as a tunable converter and i-f unit 



JANUARY 1973 



101 



between a crystal-controlled VHF or UHF 
converter and a fixed tuned i-f\ This latter 
should be a double-frequency job for maxi- 
mum selectivity and image rejection. 

The Miller three-gang tuning capacitor, 
pari no. 1 460, is such a nice little item that 

1 never had the heart to remove plates on it 
to cut down the tuning range. There also 
seems to be a big advantage in the heavy 
external capacitor padding used in parallel 
to spread the 3 -gang tuning to a little over 

2 MHz, Table 2 shows the relation of the 
number of turns on L2 to the tuning range 
obtained for the rf input circuit in the ten 
meter band. Refer to Fig. 1 and Fig. 3. 
Note that 8 turns gives over 4 MHz tuning 
range, which is more than wanted. Five 
turns, plus about 30 pF of parallel pad 
results in some 2.5 MHz of tuning range on 
the dial, which gives you a little margin at 
each end. You can cut this down to exactly 
2 MHz if you wish, Table 2 showing that 
only 4 turns for L2 gives you less than 2 
MHz of range. 

For calibration, a 28 MHz crystal oscil- 



Turns 


Relative 


Tuning Range 


on L4, Fig. 3 


Output Volts 


With 5-20 pF 


8 


2.3 


More than 4 


7 


2.3 


More than 3 


6 


24 


About 3 


5 


2.4 


2.5 


4 


2.3 


1 .5 MHz 



Table 2. Tuning range vs turns on L4 of Fig, 3. 

lator can spot 50, 144, and 432 on the dial 
for you. For example, with a 50.5 MHz 
rock, doubling several times to 404 MHz as 
a local oscillator in the 432 receiver, the 28 
MHz point on ten and the 432 point on 
432 came out on about the same black 
line, which is plenty good enough. If you 
want this unit to serve on 6, from 50 to 52 
MHz, or on 432, it works fine with its 2 
MHz spread. If you are on 2 you may want 
to cover 146 to 148 MHz as well as 144 to 
146, and then you will have to switch 
crystals in the 2-meter converter. Or build 
a second one of these jobs that covers 4 
MHz spread on the diaL The second one 
will be easier than the first! 

On 432 at present you only need a few 
hundred kHz spread, but this may change 



with the years. Right now the 432 hand 
seems to be rock-ribbed, but if a lot more 
lads get on with all-solid-state rigs and want 
the continuation of QRM-free QSCTs that 
now exist, they might get to need vfoY I 
wouldn't worry about it for a while 
though. 



MiKE* 



tuwcq to 

1.63 MHz 



D. 




Fig, 4, Diode test plank ckcuit. 

The tuning on even 432 is very smooth 
and easy with this system, and with the 
sharp 3^4 kHz bandwidth of the double 
frequency i-f described, it still remains so. 
And this is what you need on 432- 1 
remember my first work on 432 with sharp 
i-t\ when turning on or off the kitchen 
stove three floors below detuned the re- 
ceiver oscillator out of the passband. Of 
course that was using those old-fashioned 
things called tubes! I don't deny that if 
you're on the car battery and turn head- 
lights on and off, that this won't happen 
then also with this unit 

Lining Up 

Once the combination of L, Cpad, the 
Cv (variable) has been determined for the 
bandspread desired to put 2 MHz over 90% 
of the dial, the business of setting up the 
mixer and oscillator proceeded. Each Miller 
9050 coil form was stripped of its original 
winding and wound with the number of 
turns as in Fig, 3 and its coil table, and 
carefully tested, still using the setup of Fig. 
2, the block diagram. With everything 
falling into line nicely, a preponderance of 
one turn coupling links could be seen, 
indicating good match and energy transfer, 
as well as a smooth frequency curve vs* 
3-gang capacitor shaft rotation* 

The oscillator took most of the time to 
line up, but once the main points were 
found, the rest was easy. The emitter tap 
works well at one turn from the low end of 
the oscillator collector coil and the mixer 
injection voltage is best when taken off the 
same tap, thus eliminating the need for a 



102 



73 MAGAZINE 



third winding on the oscillator coil. A 3K | 
resistor can also be seen in the plus lead to 
the oscillator, because the conversion effi- 
ciency of the mixer likes it that way, with 
5-6V only on the oscillator. This also cuts 
down oscillator harmonics. 

The tuning range of the mixer input 
inductance, which is also the rf (IC 590) 
collector coil, is shown in Table 2. The 
number of turns for best gain is also the 
same, as you can see in Table 1, which is 
partly the result of design and partly good 
luck, IT1 admit, 



Lask Check Before Ganging 

What a pleasure after the tuneup battle! 
Each of the three circuits, rf, mixer, and 
oscillator, are now exactly as they will be 
in the packaged minibox version, each one 
lively, sharp tuning, with the 5—20 pF of 
the gang job tuning just over 2 mHz, in 
parallel with some 60 pF of padding, each 
dial marked with (temporarily) "28** and 
"30" MHz. So far not a trace of spurious 
or birdies anywhere. That heavy parallel 
capacity really does a job on harmonics. 
There apparently is quite a benefit with 
solid state devices in using low-impedance 
circuits, highly padded and loaded with C. 



On The Air 

As usual, when I check on ten, the first 
station heard was an African, CR6JTT, in 
Angola, Portuguese West Africa. It was 
7:30 AM, EST, which might be the reason. 
ZS6DAL was next. Wl]at a time for DX! 
These lads are just beginning to come 
through and are still calling CQ! Others 
heard were UP2KNC, UC5DF, Y06ALD 
(where in the world is that?), and Uncle 
Charlie 2KNU. Looking back to my own 
"best time'* on ten, I find it was 1947, 
which by a strange coincidence turns out 
to be almost an exact number of two 
sunspot cycles. I ran a pair of 4-250's and a 
rotary 16-element beam. If this keeps up 
1*11 find myself on ten again! 



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JANUARY 1973 



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1 • ' 



-Communication Specialists for over 34 years - 
1960 Peck Street, Muskegon, Michigan 49441 Tel. (616) 726-3196 



104 



73 MAGAZINE 



2 Meter 



6 Meter 



GENERAL ELECTRIC . . . RCA . . . MOTOROLA 



General Electric Progress Line 

450-470 MHz Mobile Units 

14" case (less accessories & ovens) 



MA/E42 



6/12 volts, 
15 watts, vibrator power supply 



nitttii i 
**< 

i*i 

mk&n * * 

w i ¥% frtfr 

• it j 1 1 1 1 



#*yi- 



<*X 



a^ ■■ 



MT/42 



12 volts, 



15 watts, transistor power supply 



I 

Accessories available for each of above units 



$30.00 



G.E. PROGRESS LINE STRIPS physically complete, but sold on an as-is basis only 





LOW BAND 


VHF 


UHF 




MA/E13 


MA/E16 


MA E33 


MA/E36 


MA/E42 


Power supply, 30W f 
less vibrator 


$20 


,^^^^_ 


$20 




$20 


Power supply, BOW, 
less vibrator 


^^^_ 


$25 




$25 


^^^ 


TX narrowband, 

less final tubes 

Note: MA/E42 wide band 


$18 


$25 


$25 


$30 


$12 


RX wide band; 
less ovens 


$18 


$18 


$18 


$18 


$12 



14" Progress Line Case, consisting of front basket and front plate with lock $10. 

Low band dual front end, 2 freq. strip $20. 

Hi-Band TPL RX with TX exciter strips less speaker, as is, missing parts S25. 

15,000 2-way FM mobile units in stock! Send for new 1973 catalog. 



GREGORY ELECTRONICS CORP 



^^POIMIC© 



The FM Used Equipment People 
243 Route 46. Saddle Brook, N J 07662 

Phone (201) 489 9000 



Dept. 73 



JANUARY 1973 



105 






For the most powerful antennas under the sun 




Go all the way into 




There's nothing half-way about the new Hy-Gain REPEATER LINE. 

Designed for the man who demands professional standards in 2 
meter mobile equipment, the REPEATER LINE is the 2 meter HAM's 
dream come true. It's got everything you need for top performance... 
toughness, efficiency and the muscle to gain access to distant re- 
peaters with ease. Reaches more stations, fixed or mobile, direct, 
without a repeater. 

The right antennas for the new FM transceivers... or any 2 meter 
mobile rig. 

Rugged, high riding mobiles. Ready to go where you go, take what 
you dish out... and deliver every bit of performance your rig is ca- 
pable of. 

261 Commercial duty 1/4 wave, claw mounted roof top whip. Pre- 
cision tunable to any discrete frequency 1 08 thru 470 MHz. Com- 
plete with 1 8' of coax and connector. 1 7-7 ph stainless steel whip. 

260 Same as above. Furnished without coax. 

262 Rugged, magnetic mount whip. 108 thru 470 MHz. Great for 
temporary or semi-permanent no-hole installation. Holds secure 
to 100 mph. Complete with coax and connector. Base matching 
coil for 52 ohm match. 17-7 ph stainless steel whip. 

263 Special no-hole trunk lip mount. 3 db gain. 130 thru 174 MHz. 
5/8 wave. Complete with 16' coax. Operates at DC ground. Base 
matching coil for 52 ohm match. 17-7 ph stainless steel whip. 

264 High efficiency, vertically polarized omnidirectional roof top 
whip. 3 db gain. Perfect 52 ohm match provided by base match- 
ing coil with DC ground. Coax and connector furnished. 

265 Special magnetic mount. 3 db gain. Performance equal to per- 
manent mounts. Holds at 90 mph plus. 12' of coax and con- 
nector. Base matching coil for 52 ohm match. 17-7 ph stainless 
steel whip. DC ground. 

269 Rugged, durable, continuously loaded flexible VHF antenna for 
portables and walkie talkies. Completely insulated with special 
vinyl coating. Bends at all angles without breaking or cracking 
finish. Cannot be accidentally shorted out. Furnished with 5/16- 
32 base. Fits Motorola HT; Johnson; RCA Personalfone; Federal 
Sign & Signal; and certain KAAR, Aerotron, Comco and Repco 
units. 



106 



73 MAGAZINE 



2 meter mobile! with 



from 



260 261 



269 



262 



263 



264 



265 






Top performance for 2 meter mobiles 

THE REPEATER LINE 

from 

HY-GAIN ELECTRONICS CORPORATION 

BOX 5407-WH LINCOLN, NEBRASKA 68505 

WRITE FOR DETAILS 



JANUARY 1973 



107 






For the most powerful antennas under the sun 





268 



2 Meter Fixed Station 

Designed for the man who demands professional standards in 2 
meter equipment. REPEATER LINE fixed station antennas are the 2 
meter HAM's dream come true. With everything you need for top fixed 
station performance... toughness, efficiency and the gain to gain 
access to distant repeaters with ease. Work many stations, fixed or 
mobile, without access to a repeater. 

The right antennas for the new FM transceivers... or any 2 meter 
fixed station. 

REPEATER LINE Fixed Station Antennas 

Tough, high efficiency antennas with a long, low radiation. For the 
top signal and reception you want... and the top performance your 
transceiver's ready to deliver. 

267 Standard 1/4 wave ground plane. May be precision tuned to any 
discrete frequency between 106 and 450 MHz. Takes maximum 
legal power. Accepts PL-259 Constructed of heavy gauge seam- 
less aluminum tubing. 

For repeater use. Special stacked 4 dipole configuration. 9.5 
db offset gain. 6.1 db omnidirectional gain. Heavy wall com- 
mercial type construction. 144 thru 174 MHz. 1.5:1 VSWR over 
15 MHz bandwidth eliminates field tuning. Extreme bandwidth 
great for repeater use. Center fed for best low angle radiation. 
DC ground. Complete with plated steel mounting clamps. 

Colinear ground plane. 3.4 db gain omnidirectionally. Vertically 
polarized. 52 ohm match. Radiator of seamless aluminum tub- 
ing; radials of solid aluminum rod. VSWR less than 1.5:1. All 
steel parts iridite treated. Accepts PL-259. 

SJ2S4 high performance all-driven stacked array. 4 vertically 
polarized dipoles. 6.2 omnidirectional gain. 52 ohm. May be 
mounted on mast or roof saddle. Unique phasing and matching 
harness for perfect parallel phase relationship. Center fed. 
Broad band response. DC ground. 

3 element high performance beam. 9 db gain. Coaxial balun. 
Special VHF Beta Match configuration. Unidirectional pattern. 
VSWR 1.5:1. 52 ohm impedance. Heavy gauge aluminum tubing 
and tough aluminum rod construction. 

8 element high performance beam. 14.5 db gain. Coaxial balun. 
VHF Beta Match. Unidirectional. Boom length 14'. VSWR 1.5:1. 
52 ohm feedpoint. Heavy gauge commercial type aluminum 
construction. 

15 element high performance beam. 17.8db gain. Coaxial balun. 
Beta Match. Unidirectional. Boom length 28'. VSWR 1.5:1. 52 
ohm feedpoint. Extra-strength heavy wail commercial alumi- 
num tubing. 



338 



362 



340 



341 



231 



108 



73 MAGAZINE 



from 
Antennas with 



am 



PUNCH! 



231 



% 



\ 









N 



340 



341 



267 



338 



1 268 



WRITE FOR DETAILS 

For top fixed station performance on 2 meters 

THE REPEATER LINE 

From 

NY-GAIN ELECTRONICS CORPORATION 

BOX 5407-WH LINCOLN, NEBRASKA 68505 



JANUARY 1973 



109 




he cubical quad antenna has long been 
popular among hams because of its 
inexpensiveness, excellent performance and 
light weight. However it suffers from two 
major drawbacks - it is cumbersome and 
not very rugged. The design described re- 
duces these deficiences and even further 
reduces the quad's weight and perhaps ex- 
pense. 

The mechanical structure of the cubical 
quad serves to support two square forms of 
wire a short distance apart. The traditional 
method of construction (Fig, 1) is not 
particularly efficient, particularly as large 
torques are impressed on the boom and 



D 



HyChantz WB2HYW 
921 East 105 Street 
Brooklyn NY 11236 



A 



REN 



METHOD 




Fig. l m 

mast, leading to lack of rigidity, mechanical 
failure, etc. The design presented here (Fig. 
2) overcomes these deleterious forces to a 
large degree. A quick examination shows the 
merits of the latter. First, it uses less support 
material, thereby reducing weight, wind 
loading, and stress on the mast. Second, the 
center of mass of each side of the antenna is 
much closer to the mast, resulting in reduced 
torque in the center of the antenna, which 
might otherwise cause it to break. The 
electrical specifications are in every way 
identical with those of the traditional quad, 
and any of one's preferred techniques for 
constructing a regular quad can be used for 
this one, except of course for the fact that 
metal cannot be used for the arms, 

. . .WB2HYW 




Fig. 2. 



OF 



QUAD 



CONS 




ON 



110 



73 MAGAZINE 




X 
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X 
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THE HAM SHACK 






SB-36 



SSB/CW transceiver. Exciting- 
personalized— effortless in operation 

■ 5-digit frequency counter reads to 
100Hz • 500W p,e + p. input • 

• Separate crystal filters for USB, 
LSB— no freq. shift with SB change 

• Covers Phone and CW sections of 
80* 40, 20, 15, 10 meter bands • 

• RIT— Receiver Incremental Tuning 

• Selectable USB t LSB, CW • 

• Double conversion receiver with 
fractional microvolt sensitivity. 




X 
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X 

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Outfeatures everything in its class- 
stands apart as the most exceptional 
dollar value in 2 meter FM gear for 
the radio amateur. 

• 12 channels • 10W output • FM 
. 144-1 43MHz • All-solid-state • 

• 12VDC operation • Supplied with 
3 sets crystals, 146.34/146.94, 
146.94/146.94, 146.16/146.76 MHz. 



2 METER CRYSTALS 

Immediate Shipment on Crystals for 

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Nearly all frequencies in stock. Please add 
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JANUARY 1973 



111 



R. R Fransen VE6TW 

Box 197 

Sherwood Park, Alberta 

Canada 



IMPROVING 

THE DRAKE R4A 




The Drake R4A receiver is an excellent 
piece of equipment as it is, but a few 
minutes with a soldering iron will give even 
better operational performance. 

The modifications that follow will not 
affect the resale value of the unit at all and 
no realignment or instruments are needed. 
Before you start be sure you have located 
the right parts; these parts can be changed or 
added without touching anything else. 

In early production runs of the R4A the 
resistors R41 and R89 were respectively 
470J2 and 270J2. These resistors are in the 
S-meter circuit and control the activity of 
the S-meter. Apparently performance could 
be improved and some changes were made, 
R41 was changed to 560S2 and R89 was 
changed to 470H. After that there still 
seemed to be room for more improvement 
and changes were made by Drake once more; 
R41 was changed to 820fi and R89 was 
changed to 560H, However, the hst change 
could cause the S-meter zero pot (R42) to 
run out of range. The final modification is as 
follows; change R41 to 820S7 and change 
R89 to620n. 

I mention all the resistance values in case 
your R4A has different values yes, R41 and 
R89 are under the chassis on one of the 



small circuit boards. The numerical designa- 
lion of the 2 resistors in the R4A diagram 
has not been changed and a good look will 
show what is what. 

The above modification will make the 
S-meter performance much better and more 
realistic, and the following modification, my 
own, will improve the performance and 
output of the crystal calibrator. 

As it is the output of the crystal calibra- 
tor does not give much (if any) indication on 
the higher bands: on 10 meters it is very 
weak, certainly no indication of any signal 
can be seen with the early S-meter circuits. 
A simple diode will bring it up 3 to 5 
S-meter unils on the higher bands. Connect 
in series with CI 18 (1% pF) and between 
Cll8 and the antenna input fack a IN34A 
diode. Lifting CI 18 from the antenna jack 
and soldering the diode in series will do it. 
Just make sure the cathode of the 1N34A is 
connected to CI 18 and the anode to the 
antenna jack; if they are connected incor- 
rectly no or only slight improvement will be 
noted. No cross modulation effects were 
observed, since with the calibrator switched 
off the diode is f for all practical purposes. 

out of the antenna circuit. 

. . ,V36TW 



112 



73 MAGAZINE 



M. B. Crowley E14R 
78 Church Street 
Listowel 
County Kerry 
Ireland 




HER 



HEDG 



CLIPP 




That detector and AGC system you read 
_ about in 73 Magazine has just been 
installed. You switch on and sit back. The 
signals pour forth loud and clear. Just then 
the XYL switches on the vacuum cleaner. 
The AGC meter goes wild and nothing but 
grating noises issue from the loudspeaker. 
You are left with nothing but regrets that 
you left out the noise limiter as you hurried- 
ly reach for the reference books, only to 
find such a complexity of limiters that you 
start tearing what remains of your hair in 
despair. But hold it! Save that precious 
commodity on top. 

What you need is a noise limiter that is 
simple, effective, easy to install and will 
work effectively with any receiver. 

Let's take a look at our noisy signal just 
after detection. The noise clings fairly and 
squarely on top of both the negative and 
positive half pulses of audio signal. A circuit 



DIODE NO. I 




Fig. 1, Crystal diode noise limiter circuit. 



is then required which will conduct suffi- 
ciently to allow that precious signal through, 
but will not conduct to the noise riding on 
top of the audio signals. This circuit must 
also perform this function on both the 
negative and positive half cycles of the 
required signal. 

A well known tube circuit which per- 
forms these functions is the Dickert noise 
limiter. However, I had no inclination to fit 
yet another tube to an already crowded 
receiver chassis, and decided to try the 
circuit with crystal diodes. The circuit even- 
tually evolved as shown in Fig. 1 . 

The positive voltage, applied through the 
1 MQ resistor to the junction of the two 
diodes, will hold the diodes in a conductive 
state. The positive voltage is of such a value 
that the maximum peak of the audio signal 
will not reach a value in excess of the 
positive gating voltage, and will thus pass 
through to the next amplifier stage. 

Now iet*s see what happens to that large 
noise pulse riding in on the positive half 
cycle of our audio signal. On the positive 
half cycle, the noise pulse will be greater 
positively than the gate voltage. Therefore, 
the junction of the diodes is negative with 
respect to the detector side of the diode, 
resulting in the No. I diode ceasing to 
conduct; thus blocking the noise pulse. 



JANUARY 1973 



113 



MORE RANGE 




ESTES ENGINEERING CO. 

543 W. 184th St., Cardans, Calif. 9024T 




VHF 
UHF 



Crystal Controlled CONVERTERS for DX, FM f 
ATV, Space and other uses. Extremely sensitive 
and free from spurious responses. With A, C, 
power supply. Choice of \-F many in stock. 
Upgrade your station to JAN EL 



50 MHz 
144 MHz 

220 MHz 

432 MHz 

AH postpaid. 



2.0 dB NF 

2,5 dB NF 
3.0 dB NF 



$74.95 
$74.95 

$79.95 
$74,95 



5.5 dB NF 
Write for full details. Also pre 
amps. Ask about our OSCAR special 435 MHz 
converters. PQ Box 112 

JAN EL Succasunna NJ 07876 

LABORATORIES 201 584-6521 



TEST EQUIPMENT 



Fluke 803 Differential AC- DC Voltmeter. $150.00 
H-P 3526-A Tape Transport, for W* or I" tape: 
15/16* I 7/8, 7Vt* 15, 60, 120 in ches pe* second. 

Less heads t $400.00 

H-P 561-B Digital Printer. $85 00 

DATATOTAL U41-8 S^digil printer. . , ,$25.00 

Keithley I50A Microvolt-ammeter $100 00 

APR-4 receiver with CV-253 Tuner, 38—1000 

MHz. 1 15 v. 60 Hz. . . $175 00 

B & K 1076 Television Analyst (Flying spot 

scanner) . , . . . • *V- • . $195.00 

Brush BL-202 2-ehannel chart recorder $40*00 

Type C dual-trace plug-in for Tektronix (made 

by Hickok) . $100.00 

Type K plug-in (Hickok) $40.00 

Tektronix type L wide-band plug-in $60.00 

Tektronix type B wide-band plug-in $50.00 

^'tul _" n ftm rim fNfmp? - tftnftip ni ttttpftt* * tfutftmt'tit *\ fmri* 

JEFF-TRONICS 

4252 Pearl Rd., Cleveland, OH 44109 



SiQSE NO I 



DIODE NO 2 



A 
O 



M 



i MEG 




>4 



.Of 
UFD 



fl 



B 
-O 



t MEG 



MEG 



,'77 



l MEG. 



1 



ft! 



Fig. 2. Addition of 1 Mf2 potentiometer to aitow 
the gating voltage to be varied, 

On the negative half cycle, the reverse 
holds true, and then No, I diode will pass 
through the noise pulse- The negative pulse 
voltage will cancel out the gating positive 
voltage and thus block No. 2 diode during 
the duration of the noise pulse. In effect. 
therefore, the noise pulses riding in on our 
audio signals are blocked off, both negative- 
ly and positively, and our audio rides 
through. All this with 2 diodes, I condenser 
and 3 resistors, Diodes with a reasonably 
high back resistance are quite suitable. The 
higher the back resistance the better the 
noise limiting action, 

I take my positive gating voltage from the 
cathode of the audio output tube, which 
reads some 5V. The voltage available from 
this point may not be a suitable value for 
gating in other receiver types. A recommend- 
ed addition would then be a 1 MQ potentio- 
meter to allow the gating voltage to be 
varied, and connected as shown in Fig. 2. 
Again the user may wish to use a negative 
gating voltage. In this case just reverse the 
two diodes, 

I have thought of using the negative 
gating voltage, as taken from the AGC line. 
Provided the AGC voltage is of sufficient 
value to allow the gating effect, this is quite 
feasible and our systeift then becomes signal 
following. 

To insert in the circuit, disconnect the 
lead from the audio side of the blocking 
condenser from the detector circuit. Point A 
is then connected to this blocking conden- 
ser, and our free wire goes to point B. Point 
C then goes to our positive (or negative) 
gating voltage, to whichever supply is used. 

This noise limiter has been tried out on 
various types of noise interference with 
gratifying results and is now a permanent 
fixture in the receiver, 

., .EI4R 



114 



73 MAGAZINE 



DESIGN FOR 




J, % Herbert ZL2BDB 
3. C« Cumberland Grove 
Porirva East. New Zealand 



MPROVED AGC SYTEM 



FOR 
CW AND SSB REC 




ON 



A receiver capable of employing full age 
facilities under all modes of reception 
is essential for comfortable listening on the 
amateur and shortwave bands. Many receiv- 
ers however, employ only a simple age 
system that falls short of providing an 
acceptable performance, particularly when 
reception of CW and SSB signals is required. 
Although some excellent papers have been 
written on the subject of improved age 
systems, most of them involve relatively 
complex circuitry and are designed to be 
incorporated as a part of a sophisticated 
receiver design. I, like many other hams", 
found the need for an age system giving 
acceptable performance under all modes of 
reception that could readily be incorporated 
in homebrew receivers and transceivers. The 
system must, however, be uncomplicated by 
additional age amplifiers, **hang" gates and 
multiple controls. To meet this end the 
circuit to be described was developed; but 



first some background theory may be in 
order to show why the conventional simple 
age system is inadequate for code and 
sideband reception. 

Figure 1 shows a simple age system of the 
type in general use in the less expensive 
commercial receivers. While this system may 
give acceptable results on AM signals, it is 
unsuited to CW and SSB reception because 
the attack time for the circuit is too slow. 
For amateur purposes, the attack time of an 
age system may be defined as the time taken 
for the voltage on the age rail to reach 63% 
of the maximum value it will attain upon 
receiving a steady incoming signal. This may 
be recognized as the familiar "charge*' time 
constant for a resistor-capacitor combina- 
tion. Similarly, the decay time for an age 
circuit may be regarded as the time taken for 
the age rail voltage to drop down to 37% of 
its maximum value after the incoming signal 
ceases, 



O+V 



TO 
IF STAGES 



TO 
RF STAGES 




Fig. 1 . Typical simple age system. 



JANUARY 1973 



115 









RIG OF THE MONTH 
SUPER SURPRISE PACKAGE 




73 MAGAZINE is Giving Away 
Absolutely FREE Every Month: 

* A TRANSCEIVER 

* or a GOOD RX or TX 

* or ACCESSORIES 

* or a SUPER SURPRISE PACKAGE 



DON'T DELAY!! Get your ticket in TODAY. Better 
yet, stop by your nearest Dealer and ask him to par- 
ticipate so that you both win. You may get your 



monthly purchases reimbursed. He will gain Fame, 
Popularity and Hordes of Customers anxious to buy. 



116 



73 MAGAZINE 



RIG OF THE 




" 



HAM RADIO CENTER 

Announces! 



STOP IN 
AND 
GET YOUR 
RIG OF THE 
MONTH 
BLANK 




BMKSME«ir,SH5 



wdbrnflArw 



m 




NOW: Call your order in r and we'll pick up the 
tab for the phone call, (Minimum order $25*00) 

HOW: Place station to station call. When phone 
bill is received, forward copy along with our 
invoice covering order phoned in, we'll send 
refund check, DO NOT CALL COLLECT. 

COMPLETE STOCKS ALL NATIONAL BRANDS 
WE BUY-SELL-TRADE USED EQUIPMENT 



Write for List 

HAM RADIO CENTER, INC. 

8342 Olive BL, St. Louts, Mo. 63132 
Phone (314) 993-6060 



RIG OF THE MONTH RULES 

1. AH entries in the contest must be sent to 
73 Magazine, Peterborough NH 03458 on 
official entry blanks, unofficial entry blanks, 
imitation entry blanks, or reasonable fac- 
similies thereof. A sample entry blank, 
which is not official, nor unofficial, but is 
closely related to an unreasonable facsimile 
is illustrated below, The very best source of 
entry blanks is your friendly neighborhood 
RIG OF THE MONTH participating radio 
distributor. This is the only source of really 
FB true-blue entry blanks for this contest. 

2. The drawing for the RIG OF THE 
MONTH will be held each 15th of the 
month and all entries received after that date 
will go into the pot for the next drawing. If 
you really are hot for a Memory-Matic 8000 
you would be shrewd if you would make 
sure that your entry blank is received at 73 
Magazine between December 15th and 
January 1 5th, 

3. To be valid, an entry blank should be 
signed or initialed by your local friendly (or, 
in some cases, unfriendly) radio distribu- 
tor — the place where you spend your 
money for ham gear. Participating dealers 
will have a good supply of blanks — non-par- 
ticipating dealers will, after your bugging 
them, see the light and start to participate. 
The more participating dealers there are the 
better the contest will be, obviously. 



RIG OF THE MONTH ENTRY BLANK 



Drawing - 15th of Each Month 



Send the rig to (if I win): 
Name 



Call 



Address 
City_ 



State 



Zip 



Participating Dealer 
Am t of Purchase $ _ 
(to be refunded) 



Salesman 



Date 



LJ I am a 73 Subscriber 



[J I'd like to subscribe 



□ Nuts! 



73 Magazine is giving away, absolutely free, no strings attached, a rig each and every 
month - drawing on the 15th - so send in this entry blank. Blanks like this should be available 
from your local participating dealer or from 73. In addition to the rig of the month, the amount of 
your purchase at your dealer (marked on the entry blank) will be refunded in full, up to a limit for 
any one month of $10,000. 
Enclose self-addressed stamped envelope with request for additional entry blanks from 73. 



JANUARY 1973 



117 






ML 



MOT PAWNER DIODES 

LINfAft ICS 
DIGITAL ICS 

inttt 




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produced identifiable echoes from the moon. A 4 bay system of 
Swan 14 el. Z meter beams recently tested by &n independent Texas 
laboratory produced over 21 dB. gain. Will out-perform any 
comparable Brand C Brand X, or any other brand by at least 3dB t 
usually much more* Please write for literature. 



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47 to 58,4 MHZ r FM continuous tuning; also 2 pre- set chan. Voice 
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3 chart audio freq, amplifier for interphone & radio monitoring of 
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w schematics S5.00 

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H-33/PT HANDSET Used S5.9S Unused S7 95 

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FAIR RADIO SALES 

1016 I. EUREKA • Bo* 1105 • LIMA, OHIO ■ 4SB02 



RELATIVE AGC VOLTAGE 




OFF 



RECEIVED SIGNAL 



TIWE 



Fig. 2. Relationship between signal level and attack 
and decay characteristics of an age system. 



These attack and decay times are illustra- 
ted in Fig, 2. 

When receiving an AM signal, the carrier 
is present to regulate the receiver gain and 
the response time of the age system need 
only be fast enough to follow signal fading. 
An attack and decay time of about *15 
second is typical for AM reception. 

Under CW and SSB conditions, no con- 
tinuous carrier is present to regulate the 
receiver gain and if the attack time is too 
long, an appreciable amount of speech or 
code may be received before sufficient age 
voltage is developed to regulate the receiver 
gain. This results in an unpleasant "thump" 
at the beginning of words or code characters. 
To overcome this effect an attack time of 
less than .01 second (10 milliseconds) is 
generally considered the maximum permis- 



ATTACK LOOP 




R? 



^_ft_A_r A 


h ite 


?5M 


Ci 
fc * 


c . 


DCCAT LOOP 

j 


i 



AGC VOLTAGE 



Fig. 3. Calculation of attack and decay charac- 
teristics for a simple age system using an equivalent 
circuit. Attack time: Refer attack loop. T (sec- 
onds) = C f/iFJ x R (M) where C = CI = 1 yF and R 
= Rp + R2 = l.QM + .25M = l t 25M :*T= 1 x 2.25 
= 1.25 seconds. Decay time: Refer decay loop, T 
(seconds) = C (flF) x R (M) where C = CI = 1 tlF 
and R - Rl and R2 ~ 2.2M * .25M = Z65M .'- T = 
I x 2,45 = 245 seconds. 



118 



73 MAGAZINE 



sible for satisfactory results. It is also impor- 
tant that the age voltage does not fall away 
too fast between words or code characters, 
otherwise a peculiar "gasping" effect be- 
comes apparent, A decay time of not less 
than 1 second wiLl be satisfactory in over- 
coming this "gasping" effect. 

It is common practice to switch a larger 
value of C in parallel with the age filter (as 
shown in Fig. 1 ) to achieve two rates of 
decay, one for AM, the other for CW-SSB. 

To evaluate the performance of the 
simple age system generally, Fig. 1 can be 
redrawn in the form of an equivalent circuit 
as shown in Fig. 3. 

It can be shown that a valve amplifier 
may be represented as a voltage generator in 
series with a resistance that is equal to the 
internal impedance of the valve. Such repre- 
sentation is known as the "Thevenin equi- 
valent circuit" and is employed in Fig. 3, 
wherein rp is the internal resistance of the i-f 
amplifier that feeds the received signal into 
the age rectifier circuit. The important feat- 
ure to note here is that the valve represents a 
series resistance (rp) whose effect must be 
taken into account when evaluating the 
operation of the age circuit. For a pentode 
amplifier rp has a typical value of .25 - 1 M, 
By substituting typical values for the circuit 
components it is easy to assess the charge 
and discharge loop circuits and hence deter- 
mine the attack and decay times for this 
simple age system as shown in Fig. 3, 

It can he seen immediately that the 
simple age system falls short of the maxi- 
mum acceptable attack time of .01 second. 
The slow attack time can be attributed i 
the large amount of scries resistance in the 
age charging path and is made up of the high 
internal resistance of the i-f amplifier stage 
and the age filter resistors. The age filter 
resistor (R2) can be replaced by a diode 
which Agates'" the age rectified voltage into 
the age rail thus eliminating its ,25M resis- 
tance from the circuit as shown in Fig. 4. 
However the high internal impedance of the 
i-f amplifier still severely limits the attack 
time. 

An Improved Age system 

To speed up the age attack time^ the 
limiting effect of rp must obviously be 



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THE NOVICE MAGAZINE 




THE NOVICK is a Complete montJ fexce: - ug 
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JANUARY 1973 



119 







TO IF STAGES 



TO RF STAGE 



100 K 



RI>22M 



100 K 



.001 



.001 



Fig. 4, Circuit for an improved age system. 



reduced. The simplest solution to the prob- 
lem is to insert a cathode follower between 
the i-f amplifier and the age rectifier as 
shown in Fig. 4. The cathode follower is 
characterized by a low output impedance 
and as illustrated in Fig. 5., the output 
impedance of the cathode follower is ap- 
proximately 500£2. Since there is little 
change in the voltage gain through the 
cathode follower stage, component values 
may once again be substituted in the equiva- 
lent circuit and re-evaluation of the perfor- 
mance made as shown in Fig. 5. 

This evaluation shows that this age sys- 
tem is characterized by attack and decay 
times very acceptable for CW and SSB 
transmissions. Various decay times can be 



COLMVALENT CIRCUIT QF 6C4 
— 




AGCvQLXUSe 



Fig. 5. Calculation of attack and decay character- 
isL for *e proved v syaj using « 
equivalent circuit. Attack time: Refer attack loop. 
T (seconds) = C frlFJ x R (M) where C = C2 = 1 /JF 
and R ■ R out = SOOQ - .OOSM ;. T = I x .005 = 
.005 seconds = .5 millisecond. Decay time: Refer 
decay loop, T (seconds) = C (jiF) x R (M) where C 
= C2= 1 JUFandR = Rl = 2.2M -\ T= 1 x 2.2 = 2.2 
seconds. 



readily achieved by changing the value of 
C2. The actual value required for C2 to 
obtain a required decay time in this circuit is 
easily calculated using the following for- 
mula: C (/uF)= 2.2/decay time in seconds. 

Several values of C2 can be switched to 
achieve fast, medium, and slow decay char- 
acteristics* 

In addition this improved age system 
offers other circuit advantages: 

(1) The cathode follower has a negligible 
loading effect on the last i-f transformer and 
hence does not cause any deterioration of 
selectivity, 

(2) Because of the negligible loading 
effect on the i-f amplifier, greater gain is 
possible. 

(3) The series diode gate in the rail 
actually doubles the age voltage available 
from the cathode follower. This may be 
recognized as the half wave voltage doubler 
circuit wherein the voltage developed across 
CI on the plus ve half wave cycle is added in 
series to that developed across C2 on the 
minus ve half wave cycle. Thus, although no 
true amplifier is used, the system exhibits 
increased control due to this voltage doub- 
ling action. 

This improved age system is capable of 
excellent results on both AM and SSB/CW 
signals and has proved to be a very successful 
modification to existing receivers that for- 
merly suffered from poor age characteristics 
when receiving CW and SSB transmissions. 

. . .ZL2BDB 



120 



73 MAGAZINE 



iam P. Turner WA0ABI 
5 Chestnut Court 
Saint Peters MO 63376 



A GALLON 





HALF 





6AL 




BUCK 



Any number of articles have been 
written on the subject of using TV 
transformers in high voltage supplies. The 
usual method is to voltage double the 
entire HV winding and disregard all other 
windings in order to reduce the load on the 
transformer and thereby minimize heating 
of the core. This arrangement works well as 
evidenced by the number of these supplies 
in everyday use. 

This article will deal with a method of 
dissipating the heat generated by the trans- 
former, thus allowing greater current to be 

SHIELD SOU>£BED TO UD 




Fig. i 



drawn from a given transformer without 
danger of catastrophic failure. 

Taking a page from the Heath Cantenna, 
a gallon bucket was procured as the start- 
ing point. The transformer was stripped of 
its end bells and unused windings to 
improve heat transfer. Angle brackets were 
then attached to each side of the core at 
one end for mounting purposes. A fruit 
juice can was modified to form a shield 
clearing the core by 14 in. or so. IV2 in. tabs 
were cut in the top of the can and the end 
% in. bent to a 90 angle in order to space 
the main portion of the can about 1!4 in. 
from the mounting surface. Do not de- 
crease this dimension, it provides room for 
the hot oil to expand. 

The transformer is mounted in the 
center of the lid of the bucket by means of 
screws running through the lid and the 
previously mentioned brackets. The tabs of 
the shield are soldered to the underside of 
the lid after it is aligned with the transfor- 
mer. The primary and secondary leads are 
brought out through feedth rough bushings. 

Select a square of medium to heavy 
sheet metal the same size as the diameter 
of the bucket and after drilling a hole in 
each corner, sUver solder or epoxy it to the 
bottom of the bucket. This will serve as a 
base for mounting purposes. Clean the 
entire assembly and paint the outside flat 
black. Fill with transformer oil to l A in. 



JANUARY 1973 



121 




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Instant access to 144 frequency pairings with 
20 watts out on the new HR-212 twelve channel 
2 Meter FM Transceiver by Regency 

Specifications 

Power Output: 20 watts 
(nom.) at 13,8 V DC 

Frequency Range: 
144,148 MHz 

Channels: 12; 
crystal controlled 

Sensitivity: 0.4 uv, 
20 DB quieting 

Spurious Rejection: 60 DB 




Model HR-212 $259 Amateur Net 

Includes microphone, mounting bracket and factory 
installed transmit and receive crystals for 146.94 MHz 



for all your 2 Meter FM needs 






Model HR-2MS 8 channel 
Transcan TM with signal search 
reception and 15 watts minimum 
output. $319.00 Amateur Net 



Model HR-2A 6 channel 
transmit, 12 receive 2 Meter FM 
Transceiver with 15 watts minimum 
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Model AR-2 Amplifier boosts 

2 Meter FM output power 

300%. 

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7900 Pendleton Pike 






Indianapolis, Indiana 46226 
Regency S Meter FM — American r*ia,de at import prioes 




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above the top of the shield with the 
transformer in place. This will require a 
slight bit of quesswork. Transformer oil is 
often available from the local power com- 
pany in small quantities and at a very 
reasonable price. 

As the transformer heats up, the oil 
directly in contact with the windings be- 
comes warm and rises to the surface within 
the shield only to be replaced by cooler oil 
from the bottom of the bucket. The hot oil 
is cooled by contact with the outside of 
the bucket, which acts as a heat sink. By 
the time it reaches the bottom again the oil 
is much cooler and is ready to absorb more 
heat. 

It is my conservative estimate that in 
SSB service a 50% increase in output 
current is available without running the 
transformer at elevated temperatures. 
There is some loss in output voltage due to 
the resistance of the secondary winding, 
but this loss is small in relation to the 
increased current available, I have run 
1400W PEP using.this arrangement without 
difficulty. 

. . .WA0ABI 



122 



73 MAGAZINE 



D.M, Burrill K7JVZ 
224 13th Street 
Sparks NV 89431 



THE HW22A- 
MORE VERSATILITY 



Every owner of a Heath HE22 or HU22A can continue to enjoy full 
plume hand coverage with this modification that permits operation in 
the new 7 J 50 to 7.200 MHz sub-hand recently allocated hy the FCC. 



It can be safely assumed that the HW22A 
single bander from Heath and its equally 
popular sisters the 1 2A and 32A are in use 
by the thousands on 40, 75, and 20 respec- 
tively- 
Let us consider for the present the HW22 
and 22A 40 meter unit. This transceiver 
tunes 7.2 to 73 MHz and a very fine job it 
does. With the recent FCC decision to 
enlarge the phone bands, the owners of these 
little rigs are out in left field, so to speak. 

Here is one simple answer, L6, the vfo 
coil, is padded with a 47 pF disc capacitor, 
designated C-205, If the ground end of 
C-205 is opened by a small switch, the rig 
now tunes 7.125 to 7.240 MHz which covers 
the new SSB frequencies. No retuning is 
necessary except to peak the final tune 
control. 

The switch may be soldered directly to 
the ground lug for L6 and C205 and Ihe lead 
from C205 will reach it, no holes to bore, no 
wires to change, and the rig can be returned 
to stock condition for trade or resale in 
about 30 seconds flat. 




7^ 



VFO 

TRIM BAU6 



I 



47 



OPEN 
CLOSED 



ADD SW 

7125-7240 
72O0-7300 



/ 



m 




Fig. 1. Circuit showing the addition of a switch 

to shift the HW22A oscillator frequency. 

As an added feature one can key V5 
cathode and work a little CW for a change of 
pace. 

This little change works out nicely on the 
HW22A as it is now in use, and no doubt the 
same thing can be done with the other two 
single-banders. By the way, the switch can 
be operated by a wire brought up through 
the top of the case. Stiff piano wire works 
fine. 

. . K7JVZ 






CLOSED 
SW- 
OPEN 



72 22 

1 I I ) 1 I 1 I I I 1 I I | I I M 1 I I 



I I 



SB 

I 1 I I I I 1 I I I 



.28 



7.3 



I I I I I I I I I I 



I I I I 



7)25 



7150 



7175 



72 



7225 



7.240 



F/g. 2. New calibration scheme after modification. 



124 



73 MAGAZINE 



— 



MM 




There will never be a better time to get your 
1973 CALLBOOKS. Here are the brand new 
1973 editions — Don't delay, the next editions 
are still 12 months away. 

Get your copies today and you will enjoy the 
latest edition for the next twelve months. Put 
it off and only you will be the loser. 



The CALLBOOK is a vital part of every amateur 
radio station. Over 285,000 listings in the US 
CALLBOOK and nearly 200,000 in the DX Edi- 
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Mail orders add 50^ per CALLBOOK postage 
and handling. 

See your favorite dealer or send today to: 



RADIO AMATEUR 

ca 



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INC 



Depi b 925 Sherwood Drive 
Lake Bluff, III. 60044 



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Miami Beach, Florida 33139 



SHIPMATES SOUGHT FOR 'ROUND THE WORLD EXPEDITION 

"YANKEE TRADER" 180 foot, 1100 steel hulled vessel, formerly well known for Coast 
Guard research, is now being refitted and air-conditioned in Miami by Captain Mike Burke 
of Windjammer Cruises 1 fame. The yacht has traveled to the seven seas, and will once again 
embark on a pleasure seeking adventure around the world beginning on January 15, 1973 
for a nine month cruise following the trade winds in southern waters. Shipmates who will 
share in the adventure and expenses are presently sought for the voyage which will feature 
the barefooted informality traditional to Windjammer Cruises. She wfll visit famous, tropical 
island ports of call such as Galapagos, Easter Island, Tahiti, Bali, Madagascar, Martinique. 
The group will explore, skin dive, sightsee, take photographs, or just loaf in luxury yachting 
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day. For details and applications for the 'round the world voyage, as well as the shorter 10 
day Caribbean cruises, contact Captain Mike Burke, Windjammer Cruises, P.O. Box 120, 
Miami Beach, Florida 33139. 



Joe Burnett W3GHZ/9 
9410 Fir Drive 
Thornton CO 80229 



D-1 



HAL 

MODIFICATION 



Then our repeater group decided to 
add a CW identifier, we ordered a 
model ID- 1 from HAL Devices. After it was 
received, our technical staff put it through a 
series of tests. We discovered that its opera- 
tion wasn't quite what we'd had in mind. It 
identified on call-up, but was not designed 
to identify again unless another repeater 
caU-up occurred after a * "guard" period of 22 
or more seconds following the first call-up. 
With the identifier timer set for the three 
minute interval, the next ID then occurred 2 
minutes 50 seconds after the first ID. This 
sequence was not suitable for a 'rag-chew* 3 
machine with a five minute timer, so we 
decided to modify the ID-1. This would 
disable the 22 second "guard" feature to 
allow identification at each call-up, and then 
identify again 2 minutes 50 seconds later if 
the repeater was still in use. We felt that no 
identification was necessary when the re- 
peater was not transmitting. The modifica- 
tion would be engineered so as to make 
maximum use of existing components with a 
minimum of circuit changes. 

ID-1 Circuit Operation 

An examination of the circuit diagram of 
the ID-I reveals that the unit actually 
consists of two sections: a timer section and 
an identifier section. In order to actuate the 
identifier section, a call-up input must have 
been received, and the timer must have 
cycled through. While the identification is 
occurring, the timing circuit is inhibited. 
After the identification is complete, the ID 
section sends a RUN signal to the timer 
section to allpw it to operate again. The 



"guard" feature is the result of the timer 
section setting a flip-flop at the end of 22 
seconds, Since this flip-flop is designed to 
clear when a call-up input is received, it must 
be set before the input can make it clear. 
Any input during this "guard" period will be 
ignored. The purpose of clearing the flip-flop 
is to provide a toggle signal to the next 
flip-flop to establish a partial enable for 
another CW identification. The identifica- 
tion will occur after the timer cycles 

Modification 

We decided to modify the ID-1 to allow 
the identifier section to be actuated indepen- 
dently of the timer, but to allow the timer 
to cycle while the repeater was in use. By 
cycling the timer, an identification could be 
made to occur 2 minutes 50 seconds after 
the initial identification, provided the timer 
was started from zero at each call-up. To 
start the timer from zero, it must be reset 
after each use. This is done by applying a 
signal to the "CLEAR" inputs of the flip- 
flops which make up the timer section, 

Since the ID-1 is on a printed circuit 
board, the actual modification requires some 
care. Probably the best way to do it is to 
open the "runs"' between components and 
install wires to the new points. The runs can 
be opened with a sharp instrument such as a 
knife point- It is not necessary to remove the 
entire run, just to open it at some point. The 
new connections are made with lengths of 
small hook-up wire. Additionally, two "OR" 
gates must be constructed and installed 
adjacent to the circuit board. Bach gate is 
made up of two diodes and a resistor, and 



126 



73 MAGAZINE 



>- 



1 



E> 




22 



> 




-W\r 




^W 






Fig. 1, HAL JD-i Modification - OR gates. 

both gates can be mounted on a single 
terminal strip (see Fig, I ). 

The "runs'' to be opened are; to IC #4, 
pins 2 & 3; to IC #8, pins 2 & 3 (pins 6 & 7 
must still go to ground): to IC #1 1, pin 5; to 
IC #13, pins 9 and 12; to IC #14, pins 5 & 
9; IC -14, pin 2 to pin 3; to IC #1 5, pins 2 
&3;toIC#16, pins 2 & 3. 
Hook-up wire connections: 

"OR" gate Z2 - output to IC #1 1, pin 5; 
single input to IC #13, pin 12; Zl and Z2 
common input to IC #13, pin 9. 

Connect the "run" that previously went 
to IC #14 pin 9 to IC #14 pin 8, 

Connect a jumper from IC #14 pin 8 to 
IC #14 pin 2. 

Connect a jumper from IC #14 pin 5 to 
IC #16, pin 12- 

t4 OR" gate Zl - output to IC #4, pins 2 
& 3; single input to IC#14, pin 9. 

Also connect IC #14 pin 9 to: IC #8, pins 
2 & 3 (pins 6 & 7 still to ground); IC #15, 
pins 2 & 3; and IC #16, pins 2 & 3. 

Remove the .001 fi¥ capacitor from the 
ACTIVATE input line, and replace it with a 
47i2 resistor. 




tl 



NEW450mhz 

MOS FET PRE-AMP 



HF 450 
WIRED 

29- 




RF voltage, gain ci ttjpicolltj l$db at J J to IS volts 0.C. 
Voise &i$aKe ii typicatiu 4.5db m $upi%io\ exoss-moduta- 
t<.cn pe*jcr nmancz and qicatcx dynamic xanqe than bi~potax 
ox single-gate- FCT'j. Gxeatlsj reduces ipuAious tzponsti 
in FM iecciv£%i. Each* to-bad diodes pxotcct each gate* 
ruj*i unncanti M\ zed CF poati 30.01. fiF iin.zidi.ng <?j$ ui- 
pitt and outpiL* cix&iit on bctii h<de& of PC boaxd. GH 
apowf glass circuit boaad -iai toivex RF leakage tiuxn ot 
i/t boaxds m Sitvex plated *ox *uj*i *EF conductance, Uat- 
ed ?CA type conntctaiu* :it camea complete xitJt all 
mounting >ia>tiL*ta\* t *F jumper and detailed uisttuctionA* 
Oa.1 usual laCiiyactLon guarantee o$ course applies. 

SCAN-1 

Oe signed to plug into 
HR2 CA.ea.ting a too c 
anncl scann&ri. Mo maj* 
ax modification* Unit 
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not in uAZm 

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HARD-TO-FIND PRECISION TOOLS 

Lists more than 1700 items — pliers, 
tweezers, wire strippefs, vacuum syslems, 
relay tools, optical equipment, tool kits 
and cases. Also includes four paqus of 
useful "Tool Tips" tc aid in tooj selection. 



JENSEN TOOLS ftnd A. 

4117 N, 44th Slreei, Php«nii P Ar.io^o 85018 




JANUARY 1973 



127 



FROM NO 15* PIN 1 4 > 
a NO 16, PINS I ft 12 



ACTIVATE > 



RUN OOJ 
FROM NO. I5 P PIN 6> ) ( 



FROM NO. 15, PIN 1 1 > 




^TO NO 8, PINS 2 a 3 
NO IS, PINS 2 & 3 

NO 16, PINS 2 & 3 



> TIMER STOP TO 
NO. 4> PINS 2 6 3 



> — Pf 



OR GATES 
21 + Z2 



START 

>TO NO, I, PINS 9, ro a II 
(THROUGH A OOl pF 
CAPACITOR) 



+ 5 1 

voct 



F/g. 2. HAL JD-] modification. 



Conditions: IC #13 pin 9 high; IC #13 
pin 12 low; IC #14 pin 8 low; IC #14 pin 9 
high; IC #14 pin 1 2 low. 

The high from IC #14 pin 9 has reset the 
timer to zero, At repeater call-up, IC #14 
pin 8 goes high, and pin 9 goes low. IC #1 1, 
pins 4 and 5 are now both high, causing a 
low to be felt at IC #1 1 pin 6 ? starting the 
identification. The high from IC #14 pin 8 is 
also felt at IC #14 pin 2, which releases the 
tlip-flop for operation when a toggle signal is 
received. The tinier is still inhibited through 
*OR" gate Z I because of IC #13 pin 9 being 
high. At the end of the identification, the 
RUN signal goes low, clearing both flip-flops 
on IC #13. This releases the timer and 
inhibits the input to IC #11 pin 5. If the 
call-up was short (such as if someone keyed 
up the repeater to hear the identifier), the 
ACTIVATE line has gone high because the 
input is no longer present. Approximately 
three seconds after the RUN signal goes low, 
IC #14 pin 5 receives a toggle signal from IC 
#16 pin 12. This makes IC #14 pin l > go 
high, stopping the timer. When IC #14 pin 9 
goes high, pin 8 goes low, and IC #13 pin I 
receives a toggle signal. This causes IC #13 
pin 12 to go high, preparing IC #11 to 



respond to the next ACTIVATE input, and 
resetting IC #4 to zero through "OR^ gate 
ZL 

If the repeater call-up results in the use of 
the repeater, the ACTIVATE line will re- 
main low, holding IC #14 pin 8 high and pin 
9 low, allowing the timer to cycle. One 
minute 25 seconds after the ID at call-up, IC 
#14 pin 1 2 goes high as a result of the toggle 
signal from IC #15 pin II. If the repeater is 
still in use 2 minutes 50 seconds after the 
initial ID, IC #14 pin 12 goes low again 
because of a second toggle from IC -15 pin 
I 1. This provides a toggle signal to IC #13 
pin 5, making IC #13 pin 9 high and causing 
a second identification to occur. The flip- 
flops in IC #13 are then reset by the RUN 
signal, preparing the ID-1 for another CW 
identification after 2 minutes 50 seconds. 

This modification has been described in 
some detail in the hope that other repeater 
groups might benefit from the work of the 
W0JGL repeater technical staff. When you 
come to Denver, bring a set of crystals for 
07/67 with you. Ours is an open machine, 
and we welcome visitors. We may not be 
number one yet, but we're trying harder! 

. . .W3(iHZ/0 



128 



73 MAGAZINE 




~Or*&- **&*■ '*&*. 



*&-*&- r ^-'^-*&*^>'~&'.<j&*.-j&'.*.&r.i&~<'^.i&- 1 .u&>i*&x 



WALLER ELECTRONICS 
TEST EQUIPMENT SALES 

P.O. Box 9913, Chevy Chase, Md. 2001 5 

Telephone 301-652-0996 



The "TESCO-FAD" has no 
tuned coils to go off frequency, 
no tuning necessary or even there' 
Its all in one "Black Box I.C." 
ready to go. The * TESCO-PAD" 
has a 1 second hold up for your 
transmitter, complete P.T.T. 
operation, available with dual 
audio output levels, 12 or 16 tone 
combinations. 

KIT S29.95 334,95 Wired 

(Add $1.00 for 16 tone version > 
($2.00 for dual output version! 




NOW BRUTE FORCE IN A 12V BENCH SUPPLY - THE WALLER 60 AMP 12 
VOLT SUPPLY! 

A bench power supply for mobile equipment* This brute of a supply will run a 
mobile rig and even an amplifier from 1 10V ac. The output is a nominal 12V dc at 
50 amps and is usable to a full 60 with a slightly lower output voltage. The heart of 
this supply is a constant voltage transformer rated at a constant output of 60 amps. 
The supply features built in voltage and current metering. The Waller 12 volt 60 

amp supply is only S100 in kit form or S125 wired. 

Portable Tune Up Meter with cables to plug into Motorola, Link, GE, Standard, etc. 
This unit gives you the meter functions of the radio being tested. It also operates as 
a portable dc voltmeter with the following full scale ranges: 1.5, 5, 15, 50, 150, 
500, 1 KV with a special 3 volt range for GE Progress Line equipment. The UT-1 
can be set zero center for discriminator readings, Also featured in the UT-1 is a field 
strength meter. Place your order now. Kit form $42.50. Wired $49.95. Extra cables 
of your choice (specify rig) $4,00 ea. 



CALL OR WRITE WALLER NOW 






^ — ■ ^ ^^ ■ ' » 



\*&-><jy- 



4v^^ 



Bernard Harris, Jr. K4PR T 

P.O. Box 111 

Fork Union VA 23055 



D 



0LAR0ID 




RIN 



COPIER 



ORSST 




Having been on SSTV for a little over 
one year now and using the Robot 
SSTV equipment I have found that at times 
I desired a quick way to write calls, focus on 
pictures, etc., without having to use the 
magnetic letters that I have. I wanted some- 
thing that I could insert a small card or 
picture in and then focus the Robot camera 
on for transmission of pictures. Such a 
device would have its own light source so 
that external lighting would not be required 
and it would also have its own lens so that 
close-up lens for the Robot camera would 
not be required. 

Before going to the drawing board and 
work bench to build such a device, I decided 
to look around the shack to see if 1 had 
anything I could modify that would meet 




Polaroid Print Copier before modification showing 
the door that must be removed before copier can 
be used for SSTV. Notice the 2 nuts just below the 
lens — these are to be removed along with the pin 
that holds copier door to the body. 



my requirements. For several years I have 

had a Polaroid Print Copier, Model 230, 

which was used with the old Model 80 

Polaroid cameras to make copies of Polaroid 

prints. The copier has its own light source 

and its own lens. The only problem that I 

could see with using the copier as it was 

originally designed was that it had a large 

door (see photo) that must be removed in 

order that the Robot camera could be placed 

close to the copier to focus the Robot 

camera on the picture or writing that I 

wanted to be transmitted. 

It is a simple matter to remove the door, 

which also has the lens attached to it. All 

that is required is the removal of the two 

nuts that hold the lens frame to the door 

and the removal of the pin that hinges the 




Close-up of Polaroid Print Copier showing lens, the 
2 nuts that must be removed, and door hinge (pin 
must be removed). 



130 



73 MAGAZINE 




Polaroid Print Copier after door was removed. 
Notice the two nuts on lens door — these are 
removed — merely shown here to indicate the ones 
that were removed. Lens door is glued back in 
place. 

door to the body of the Polaroid Copier. 
With this done, you will now find it neces- 
sary to put the lens back, but this time 
without the door. Put a small amount of 
glue around the lens frame and place back 
on the Copier. The Polaroid Copier is now 
ready to be used with SSTV. 

To use the Robot SSTV camera with the 
Model 230 Polaroid Copier first set the 
Robot lens to infinity and place the lens of 
the camera to the lens of the Copier as 
shown. Place a picture or small card in the 
Copier, turn on the light in the Copier, 
adjust lens opening of the Robot camera for 
the amount of light needed, and you are 
ready to transmit SSTV pictures. Some 





Picture made using the Polaroid Print Copier for 
SSTV. 

experimenting will be required to see just 
how much writing can be used and the size 
of the picture that you can use, but this can 
be determined without much difficulty. 




Robot SSTV camera and Polaroid Print Copier 
being used to transmit SSTV pictures, 



Picture that was used to make transmit picture 
using copier. Notice that in previous photograph 
only the head was actually transmitted. 

As for acquiring one of the Polaroid Print 
Copiers - Model 230 - it should not be too 
difficult. The copiers cannot be used with 
the newer Polaroid cameras, and this particu- 
lar model was designed to be used with the 
Model 80 Polaroid camera. It is my under- 
standing that there are not many of the 
Model 80 cameras being used as it is rather 
hard to acquire films. The original cost of 
the Model 230 copier was about $29.95. It is 
suggested that if one of the copiers is desired 
that you contact some of the large photo- 
graphic dealers, 

. . . K4PRT 



JANUARY 1973 



131 



■~i 



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Both AC and DC operation t8 waits) 
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* Write to us for the most competitive package price in the West. 



132 



73 MAGAZINE 




Chuck Mines K6QKL 
8615 I del wood Dr SW 
Tacoma WA 98498 



THE 



RROUS WHFF 



CW 




UMP 



Unless tradition has grasped you by the 
throat or your concern for CW is 
limited by your gag reflex, you have a more 
than passing interest in the use of electronic 
keyers. They don't seem to inspire the sort 
of affection one feels toward a good receiver 
of faithful beam. Still, the keyer invokes the 
fascination of any good gadget. Push a 
button, turn a knob, and watch the thing go 
all by itself, The integrated circuit with its 
micro gates and flip-flops has made the 
keyer attractive to the amateur. The prob- 
lem is mostly in what one uses to key the 
keyer. 

Three states are selected by that device; 
dots, dashes, or nothing. Most keys are 
mechanical variations of the old straight key. 
A "paddle 1 * is mounted so that motion or 
compression cause physical contact which in 
turn allows electrical conduction. A lot of 
silver and gold plating goes on those contacts 
in order to reduce their switching resistance. 
Even so, intermittent or unreliable keying is 
a frequent result. Keys of varying quality 
and reliability are commercially available- 
Flip through the ads. Note the swell prices 



on those joules. Eighteen to twenty-six 
bucks is about all you can get them to take 
for a key. Motivated by the usual theological 
conviction that money should remain in my 
wallet, I set out to build my own. The 
ferrous wheel CW pump was the result, and 
its construction is recounted here for your 
convenience and continued solvency. 

The first problem is to get a reliable, low 
resistance switch. That has to be mighty low 
because the magnitude of the currents being 
switched is inordinately small when com- 
pared with the stuff we're used to switching 
around the shack. The magnetic reed switch 
has the admirable qualities required for the 
job. Hermetically sealed, able to cycle in a 
millisecond and handle up to an ampere, 
works in any position — and has a contact 
resistance in the order of 50 milliohms. 
Since the gadget is sealed, we won't have to 
worry about the contacts oxidizing and 
increasing in resistance, or dirt or stray fur 
from the cat getting inside. The switch 
configuration is sketched in Fig, 1 . Just two 
pieces of overlapping metal mounted in a 
glass cylinder. The switch is normally open. 



JANUARY 1973 



133 



r\ 



$<n C loses 
*j sw opens 

'X MAGNET N. 



REED SWITCH 
AND 
'FERROUS WHEEL* 



V 



REED SWITCH 



F/g. I. Traditional reed switch configuration — two 
pieces of overlapping metal in a glass cylinder 
activated by bar magnet. 

and it is closed by moving a magnetic field 
into proximity to the middle of the cylinder. 
Reed switches come in different sizes and 
cost $1 or less. The reed switch has an 
imperfection, though. In Fig. 1 a bar magnet 
is brought up to the switch, and the switch 
closes at the distance indicated. As the 
magnet is withdrawn from that point the 
switch doesn't immediately open, however. 
The magnet has to be removed to the second 
position shown before the switch opens. 
This is inconvenient behavior. Clearly a key 
wouldn't function in an orderly fashion just 
by sloshing a bar magnet around in proxi- 
mity to a pair of reed switches. Pity, 

A solution was found in a doughnut 
shaped magnet. Vm calling this doughnut 
shaped magnet a ferrous wheel in order to 
make sure you or someone else doesn't 
confuse it with the ferrite toroids upon 
which sundry transformers are wound. The 
ferrous wheel is a genuine magnet. It has two 
poles. Two of them placed close together 
will either attract or repel one another — 
depending upon how they are oriented at 
the moment. The field of a ferrous wheel is 
quite different from that of a bar magnet f 
and you may enjoy sprinkling some iron 
filings on a sheet of paper and examining 
that field . . . 

Now take a look at Fig, 2. A ferrous 
wheel is slowly moved with respect to a reed 
switch extended through the "hole of the 
doughnut/' As the switch first enters the 
hole, the reeds close and then open again. 
This is not the switching region we want to 
use. Continue until the ferrous wheel ap- 
proaches the center of the switch. You'll 
hear it click closed. With the switch centered 
in the wheel move one or the other and 
measure the total travel of the wheel neces- 




Fig, 2. Reed switch activated by "ferrous wheel' 1 
magnet, 

sary to allow the switch to open again. This 
distance is going to vary with the strength of 
the particular magnet involved, its shape, 
and the inside diameter of the hole. The 
minimum travel required on the wheels I 
used is three thirty-seconds of an inch. 
That's hardly the most sensitive switching 
device to be produced by contemporary 
primate technology. Still, it functions very 
nicely when configured as a pump. 

There are a number of possible ways to 
configure a switch usable for keying pur- 
poses. For the preservation of symmetry I 
built the ferrous wheel CW pump pretty 
much as you sec it lurking in Fig. 3. Now, if 
you bought your last key in 1927, and have 
had it anchored to the desk top with three 
wood screws ever since, this may take some 
getting used to, Don't rush it, Sit back and 
glare and let your stomach settle. The key 
begins with a pair of bearings mounted in a 
bearing block of some sort. A shaft extends 
through those bearings, and non-radial mo- 
tion is prevented by a pair of keepers 
mounted on the shaft, At the near end of 
the shaft a knob is mounted, The far end of 
the shaft is fastened to the middle of a mast, 
and a ferrous wheel is mounted at both ends 
of that mast. Stand-offs are placed on the 
baseplate and one lead of a reed switch is 
soldered to each stand-off leaving the free 
end of the reed switch to extend vertically 
through a ferrous wheel. When force is 
applied to the knob, torque is placed on the 
mast, moving a ferrous wheel down over a 
reed switch causing the contacts to close. To 
allow the bar to return to its original 
position when force is removed from the 
knob, the repelling field of two oppositely 
polarized ferrous wheels is used. Since the 
forces balance on each side, they act much 
as two springs. Keying the pump unbalances 



134 



73 MAGAZINE 



the forces between the opposing magnets. 
Releasing finger pressure allows the mast to 
return to its static, balanced condition. 

Construction 

The picture should answer most of your 
questions. For the most part the key is 
constructed of certified rubble and litter left 
on the basement floor from old projects. 
The base is a piece of fiberboard; the bearing 
block, two pieces of plastic bolted together 
and glued to the base. The mast and lower 
wheel supports are Vi in. balsa wood. The 
magnets used are from the toy counter of 
the local hardware store, come four to a 
pack, and are called "Magic Rings/' There is 
nothing particular or special about them; use 
the lightest, strongest ones you can find. The 
reed switches used are GE-X7 packs available 
in the General Electric Experimenter line. 
(Very small reed switches are mounted in 
the reed relays available from Poly-Paks. 
There are four reeds inside the coil winding, 
each % in. long, and they should be removed 
with great care if you plan to use them in 
this application.) The most reasonable 
source of bearings is surplus. You need two 
that wUl fit available shaft material. They 
usually fit tightly on the shaft, and the shaft 
must be carefully debarred after cutting. 
The shaft must turn freely in the bearings, 
and keepers are needed to keep the shaft 
from sliding out of the bearings. The pump 
is a cut-and-try affair and measurements are 
after the fact. The balsa mast is notched and 
the wheels glued in place with airplane glue. 
Wheel spacing is 7 in. center to center. Use 
what you like. If the mast is too short you'll 
lose mechanical advantage — and if it is too 





What K6QKL's Ferrous wheel looked like when it 
was done. All this beauty and it works, to . . , 



Fig, 3. Configuration of K6QKL's ferrous wheel 
CW pump, 

long sensitivity is increased but there is a 
tendency to mechanical oscillation. Color 
code your wheels with a dab of paint so you 
can recognize their north and south poles. 
Mount the wheels with the polarity orienta- 
tion shown in Fig, 3. Like poles must be 
adjacent to one another. Put the properly 
polarized bottom wheels over the stand-offs 
and solder the reeds in place. The gap 
between the top and the bottom wheels is, 
again, a matter of taste. Mine ended up 
about 10/32 in. apart. 

Adjustment from this point on is a matter 
of piddling with spacing and balance and is 
most easily done by moving the reeds or 
bottom wheels up and down. When the mast 
is balanced both switches should be open. 
Pressure on the knob should close the switch 
with little movement. Equal pressures should 
close each switch. If the force required on 
the knob is too high, increase the gap on 
both sides between the wheels and their 
repeUers. Be quite sure the repellers are 
mounted low enough so that they don't 
cause the reeds to close. 

The ferrous wheel CW pump in the 
picture was built to see if an idea would 
work, and it did. Having established that, 
there is no reason yours should be so 
barbaric in appearance. With about five 
minutes' reflection you should come up with 
at least two other possible configurations of 
such a key, using essentially the same switch- 
ing method but a different mechanical 
arrangement, construction technique, and 
materials. Try them. This is inexpensive 
ground to dabble in, and it is always 
rewarding to build something in a different 
fashion and discover that it works. 

. .K6QKL 



JANUARY 1973 



135 



, . , NEW PRODUCTS - continued 

The output circuit features a band- 
switch with 20 A silver contacts 
switching a heavily silver plated coil. 
A vacuum variable is used for plate 
tuning, T/R switching is fast and 
quiet — full break-in is a panel selec- 
ted function — through the use of 
vacuum relays. 

If you are seriously in the market 
for a fine linear, write Payne Radio, 
Box 525, Springfield 77V 37172. 

LOW LOSS COAXIAL CABLE 





Blonder-Tongue has developed a 
new line of coax cables for cable 
television networks. Twelve new types 
are available including RG 59, RG-6 
and RG 11. Their top-of-the-line 
#4851 featues 12 gauge copper-clad 
aluminum center conductor and alu* 
minum tape shielding with 50% alumi- 
num braid. This particular cable has 
an attenuation factor of only 1.6 dB 
per 100 ft at 470 MHz! The RG-59 
and RG-11 types, while not perform- 
ing quite as well as the -4851, offer 
improved loss characteristics over 
regular foam types. They could be 
used to a high advantage where VHF 
or UHF installations require long 
lengths of cable. For more informa- 
tion write Blonder-Tongue Labora- 
tories, One Jake Brown Road, Oid 
Bridge NJ 08857, 

CW FILTER 




IfTB 



\J 



Autek Research has come out with 
a new audio filter that is going to be a 
big help to Novices and serious CW 
men alike. Their "Q*Box" is self- 
contained and affords variable audio 
selectivity from approximately 2 kHz 
down to 30 Hz by a simple twist of 
the selectivity control. There is no 
insertion loss and the output is high 



enough to drive headphones or an 
external speaker amplifier. 

This unit is a must for anyone using 
an inexpensive receiver or a sideband 
transceiver in our crowded CW bands, 
All you have to do to put it into 
operation is to plug it into the head- 
phone jack of your receiver, plug your 
headphones into its output plug, and 
turn the selectivity control to the 
desired amount of sharpness. This is 
made possible by Autek's use of a 
transistorized active filter that passes 
tones near the design frequency of 
800 Hz and rejects ail others (namely 
all that QRM right next to that weak 
signal you are trying to copy). The 
circuit is powered by an internal 9V 
battery and requires no power from 
your receiver. 

When the Q-Box arrived at 73, I 
immediately rushed it downstairs to 
the ham shack and connected it to our 
Signal/One. Tuning to the 40 meter 
Novice band/traffic- jam and adjusting 
the selectivity control back and forth 
only affirmed my suspicions . . . the 
Signal /One has an awfully good receiv- 
er section all by itself! The G-Box did, 
however, act as a fine trimming selec- 
tivity control . . . it would be very 
useful in contests and when condi- 
tions really get rough. 

After scrounging around a bit in the 
back workshop, I came up with an old 
home-brew receiver that someone had 
packed away years ago. Here was an 
excellent receiver with which to test 
the Q-Box. It had two i-f stages at 
1700 kHz and the selectivity was 
bound to be awful. It was. The situa- 
tion in the 40 meter Novice band was 
so jumbled that only exceptionally 
strong signals were readable. This was 
going to be an acid test! I plugged in 
the Q-Box and turned the control to 
maximum , . . what results! Each sig- 
nal now occupied a tiny space in the 
spectrum. I had to back off on the 
selectivity control a bit, for the receiv- 
er just wasn't stable enough to use all 
that selectivity. Signals kept drifting 
out of the 30 Hz "slot" and would 
disappear. After adjusting things for a 
good balance between selectivity and 
ease in tuning, I went looking for 
weak signals. I found one that was 
perfectly readable and, seemingly, all 
alone. Was 1 ever wrong. Backing off 
on the Q-Box control caused that 
nicely readable signal to be clobbered 
by strong QRM that was lurking just 
out of the sharp bandpass. Being 
suspicious, and just to prove to myself 
that the QRM didn't just appear at the 
moment I turned the control, I turned 
the selectivity slowly up again. Just as 
slowly, the signal started climbing its 
way out from under the QRM and 
became copyable again. 

The variable selectivity feature of 
the Q-Box is really a plus if you have 



had any experience with surplus 
toroid filters. The torotd filters could 
be switched either fully in or fully 
out. This caused problems if the de- 
sired signal was not tuned exactly on 
the nose, for you usually had to go 
looking for the signal all over again 
once the filter was switched in. With 
the Q-Box, the selectivity can be 
applied gradually as the receiver 
tuning is touched up to keep the 
desired signal centered in the ever- 
narrowing bandpass. The selectivity 
can also be tailored to the prevalent 
band conditions. If maximum selec- 
tivity is not needed, the control can 
be adjusted to a medium that allows 
good copy and effortless tuning. 

While not quite as good as a steep 
skirted mechanical or crystal CW filter 
installed at the if level of a receiver, 
this audio filter can make the big 
difference between copy and no copy 
during bad QRM . . . especially if you 
don't have that expensive mechanical 
filter* $17.95 from Autek Research, 
Box 7494, Canoga Park CA 91304. 

WIRELESS RECEIVER 




No, this is not a grand announce- 
ment of the invention of radio. In 
fact, the new receiver offered by 
Lowcom Systems doesn't make use of 
radio waves at all. Operating on the 
principal of simple audio induction, it 
enables anyone to set up a reliable 
short range communication system for 
the home, shack, or even small busi- 
ness. 

it works like this: A large audio 
field is generated. This is easily accom- 
plished by stringing a wire around the 
area of proposed usage. The wire is 
fed by the audio from a ham receiver 
or PA amplifier and the volume is 
adjusted until a comfortable signal 
level ts heard on the Lowcom unit. As 
long as you stay within the audio field 
you are in range. The larger the field, 
the larger the range. 

One use that can immediately be 
thought of is repeater monitoring. 
Since repeaters are usually monitored 
continuously, every stray squelch-tail 
and "QRZ" echoing through the 
house just brings the situation closer 
and closer to divorce court. Why not 






136 



73 MAGAZINE 



make everyone happy? Just string a 
wire around the outside of your attic 
and feed it with the audio from your 
FM rig . . . plug the Lowcorn earphone 
in your ear , . . and walk around 
smiling. Do the same while you are 
waiting for the HF net to get started. 
No need to turn the audio gain way 
up while you are eating dinner. Just 
listen in on the Lowcorn. No one will 
know the difference until half way 
between mashed potatoes and pie 
when you leap from your chair head- 
ing for the shack. 

The unit is available for $15,95 in 
kit form or $24.95 wired from 
Lowcom Systems, 10727 Indian Head 
Industrial Blvd., St Louis MO 631 3Z 

TEN-TEC LINEAR 




TEN-TEC Inc. has announced the 
introduction of the Model 405 Linear 
Amplifier to their line of amateur 
radio equipment- Completely solid 
state, the amplifier delivers 50W of 
power to the load in the frequency 
range of 3,5 MHz to 30 MHz when 
driven with less than 2W. Features 
include broad band design, two panel 
meters indicating rf power and stand- 
ing wave ratio, exciter-actuated 
changeover relay with adjustable delay 
time and 12V dc operation. Its small 
size and light weight make the ampli- 
fier ideal for use in portable, mobile, 
marine and aircraft applications. The 
price is SI 49.00 — ac power supply is 
$49.00. Write to TEN*TEC Inc., High- 
way 411 East, Sevierviffe TN 37862 
for further information. 

TEN-TEC RECEIVER 




• ti* i bU, Inc. has announced the 
introduction of the Model 315 Com- 
munications Receiver to their line of 
amateur radio equipment. Completely 
sofid state, the receiver covers the 



amateur bands between 3.5 MHz and 
30 MHz, Features include permea- 
bility tuning, linear frequency read- 
out, 9 MHz crystal lattice if, pulsed 
crystal calibrator and low noise 
MOSFET rf amplifier and mixer. 
Built-in regulated 115V ac power sup- 
ply can easily be converted for 12V dc 
operation. An accessory pfug-in audio 
filter is available to narrow the band- 
pass to 300 Hz for CW reception. 

The Model 315 was designed for 
the amateur who demands the exact- 
ing requirements for DX, traffic, con- 
test, net and general operations, as 
well as the beginner. Price is $229.00. 
Model 235 CW Filter is $14.95. For 
further information write to TEN- 
TEC Inc., Highway 411 Bast 
Sevierville TN 37862. 

PORTABLE TEST LAB 




The Lee Labs Dynamic Serviset is 
quite a little piece of equipment It is 
basically an rf/af signal tracer, but 
with a horde of extra features. Built 
into it is the ability to test the prsence 
of ac or dc voltage and substitute 
three different ranges of resistance 
and two ranges of capacitance. It can 
also test the resistance of a particular 
circuit and even determine the leakage 
of a capacitor. The amazing thing 
about this device is its ability to make 
fairly accurate checks on circuit con- 
ditions without the need for extra 
(expensive) equipment 

Because it is self contained, the Lee 
Serviset makes troubleshooting really 
easy. This is especially true when 
working on tiny printed circuit 
boards. The work area doesn't have to 
be cluttered with a tangled mess of 
test leads coming from VOMs, resis- 
tance substitution boxes and tran- 
sistor checkers because you can per- 
form all those functions with one 
hand held unit. Functions are selected 
by repositioning a single test load. 

Suppose you have traced a signal in 
a malfunctioning receiver up to, say, 
the second i-f stage, but you lose it as 
you go on to the next. By changing 
the test lead position on the Serviset 
you are able to use it as a voltmeter to 
check the corresponding voltage levels 
at different points at the if tube or 
transistor If no voltage appears at the 
plate, the Serviest can then be used to 
check the condition of the load resis- 



tor and bypass capacitor. If one of 

these are found faulty, the unit can 
quickly substitute a value to confirm 
the fact by restoring operation. 
Sounds easy? It is, 

The Dynamic Serviset is manu- 
factured by Lee Electronic Labs, 88 
Evans Street, Watertown MA 02172 

450 MHz YAGI 




Cush Craft has just introduced a 
new 6 element rear mount 450 MHz 
yagi for amateur FM repeater opera- 
tion. It can be used for control links 
and stations for monitor applications 
and access to 450 MHz repeaters. It is 
priced at SI 0.95 amateur net and 
exhibits 10 dB gain. It has direct 50:2 
Reddi Match feed with built-in coax 
fitting. The boom is 35" long and 
overall weight is 3 lbs. Model No. 
A449-6 is available through all Cush 
Craft distributors. The antenna is also 
available for commercial service. Cush 
Craft Corp., 621 Hay ward St., Man- 
chester NH 03103. 

SOLID-STATE SWL RECEIVER 










Heath Company, world's largest 

manufacturer of electronics, has 
brought to market a new professional 
solid-state SWL receiver, the Heath kit 
SB-313. The unit covers 9 switch- 
selected shortwave bands between 3,5 
and 21.8 MHz; receives SSB, CW, and 
AM with professional performance. A 
5 kHz AM crystal filter is supplied 
with the kit, with separate SSB and 
CW crystal filters available as optional 
accessories. Outstanding stability, 
selectivity and sensitivity are the re- 
sult of advanced -design all solid-state 
circuitry including 19 transistors — 
four of which are MOSFETS; 11 
oscillator crystals and one IC. Pre- 
assembled and aligned Heath LMO 









JANUARY 1973 



137 



offers good linearity and highly stable 
tuning. Large dial calibrated in 1 kHz 
increments makes for easy tuning. An 
IC crystal calibrator provides markers 
every 100 kHz or 25 kHz. Other 
features are a transistor-regulated 
power supply for stable voltage to all 
oscillators under varying line and load 
conditions; an rf attenuator that 
allows adjusting sensitivity for best 
signal handling; virtually backlash-free 
dial tuning; modular plug-in circuit 
boards plus ready-to-use wiring 
harness for easy assembly; and special 
extender boards for troubleshooting 
even while set is operating. An 1 1 Mil 
input VTVM f and 812 speaker or 
headphones, and an antenna are all 
that are required for alignment. 

Kit is mailorder priced at $339:95 
RO.B. Benton Harbor. For further 
information, write Heath Company, 
Benton Harbor, Michigan 49022. 



"B" SERIES BASE 
STATION COLLINEAR 



i # 



M" SERIES MOBILE 
GAIN ANTENNA 




The "M" Series antenna by Anten- 
na Engineering is a full 5/8-wave length 
vertical whip with a bottom- load 
matching transformer. It is designed 
for vehicle-mounting in a 3/8-inch 
hole. The adjustable threaded bushing 
allows for either roof-mounting or 
through double-panels. The matching 
transformer is encased in a fiberglass 
sheath which is nearly indestructable. 
The whip is of 1/8- inch spring- temper 
type 302 stainless steel; the coil tip 
unscrews to accept a chrome-plated 
spring (optional at extra cost) for 
severe service applications. 

This antenna is available for all 
amateur frequencies in the 146, 220 
and 440 MHz bands. The "M" Series 
antennas are at dc ground for dissi- 
pation of static, and ate supplied with 
20 feet of type 58A/U coax and UHF 
connector. Prices range from $16.95 
for the 2 meter version to S15.95 for 
the 3/4 meter version. Contact Anten- 
na Engineering Cc. f Inc., P.O. Box 
19449, Indianapolis, Indiana 46219. 




The "B" Series antenna by Antenna 
Engineering is a triple-skirted collinear 
antenna operating with a decoupling 
ground plane. These are seven quarter 
wavelengths, designed for vertical 
polarization, and are available for ail 
amateur frequencies in the 146, 220 
and 440 MHz bands. Unlike many 
antennas of this type, the "B M Series 
is at dc ground for positive lightning 
protection, and the gamma-type feed 
is located on the radiating structure 
for symmetrical current distribution. 
This feed system will match 25 to 100 
ohms for use with various transmis- 
sion lines and in phased-arrays, 

The supporting mast is heavy-wall 
6061-T6 aluminum alloy, and the 
radials are spring-tempered type 302 
stainless steel. A mounting receptacle 
is provided for 1-inch l\IPT_.pipe- The 
unit is quite rugged for its light 
weight Termination is by type 8/U 
coaxial cable. Prices range from 
S39.95 for the 2 meter version to 
$29.95 for the 3/4 meter version. 
Contact Antenna Engineering Co., 
Inc., P.O. Box 19449, Indianapolis, 
Indiana 46219. 

DUAL BEAM SCOPE 



£>) 




This new Philips instrument is 
offered at approximately S900 as the 
successor to the widely used Philips 
PM3230 for a wide variety of applica- 



tions in industrial electronics includ- 
ing telecommunications, television, 
education, computers and peripherals, 
and electronic maintenance. 

The PM3232 combines a number of 
features that can often eliminate the 
need for a more expensive, higher 
bandwidth instrument when only one 
or two individual features, such as 2 
mV sensitivity across a wide band or 
dc triggering, are required for a parth 
cular application. In addition to being 
a true dual beam instrument and 
therefore having no possibility of 
phase displacement between the two 
traces, the PM3232 also offers univer- 
sal triggering facilities including auto- 
matic level, dc coupling, and auto- 
matic TV line/frame selection. Its 
sensitivity is 2 mV/cm everywhere in 
the 10 MHz bandwidth of the instru- 
ment. The newly designed Philips 
CRT has a large 8x10 cm screen and 
excellent light output dervied from 
the post-deflection acceleration sys- 
tem so that even low duty-cycle, 
fast- sweep signals are displayed 
clearly. Detailed information on the 
PM3232 and on the entire line of 
Philips instruments available in the 
U.S. may be obtained by writing to 
Test & Measuring Instruments Inc., 
224 Duffy Avenue, Hicksvilfe, N.Y. 
1 1802, 





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RTTY ART 

Here is an example that originated 
with Don WA6PIR. Have any good 
examples that you want to see in 
these pages? 



138 



73 MAGAZINE 




I insist 



don't ever proof r 

roles HreE^i^^n 

n 
that you print ev 




THE COVER... 

My husband is a ham and enjoys 73 
very much. On occasion I will pick up 
one and read a few articles and enjoy 
them also. 

I ran across the Letters section of 
the December 1972 issue that i would 
like to comment on. 

After reading Mrs. Shera's letter 
about the October cover I decided to 
conduct a little experiment, I asked 
my husband his thoughts on the 
October and November 1972 covers. 
He thought the "equipment" was 
really outstanding. My husband is an 
admirable man and only has the best 
of intentions. 

Therefore, I'm sure there were no 
adulterous thoughts lurking in his 
mind. If a man gets to where he 
doesn't enjoy looking at a pretty girl, 
my best suggestion would be to find 
the closest mortician I 

I would like for you to please give 
equal space to Mr. Shera and let us 
hear his opinion of the covers in 
question. 

Keep up the good work at 73 and 
please use a picture of Burt Reynolds 
on one of your covers to please the 
lady readers of your magazine. Who 
knows, Mrs, Shera might like that 

Mrs, H. Hogan, jr. 
Cher aw SC 

But then , , , would your husband 
write us a nasty letter?? 

Sent in my renewal last week r and 
after getting the November issue to- 
day, I am glad I did. 

About your new cover format, 
that's a cute rig she's holding, but my 
non-ham O.M. is beginning to wonder 
about the magazines I subscribe to! I 
suppose with the small number of 
licensed YL's, we'll have to resign 
ourselves to being addressed as "Mr/' 
or "O.M," - but couldn't you at least 
refer the cheese cake minded to a 
different magazine? Or at least give us 
YL's a good looking man to look at! 

Mary Hay ties WB8MA V 

Normally I'm not a complainer, but 
lately the YL has become very sus- 
picious with all the brown-wrappered 
73's which have appeared at the door. 
Naturally, when I tell her that it is 
only 73 Magazine, a radio magazine, 
she looks at the cover and doesn't 
believe me, because of accessories 
often attached to the equipment, 
which aren't often included in the 
purchase price of the otherwise — I'm 
sure — good equipment. It has oc- 



curred to me that maybe you ought to 
put a centerfold in 73. However, to 
please the YL, it should be some 
complicated circuit, instead of a com- 
plicated blond, like "that other maga- 
zine." It's not that I have anything 
against blonds (after all, they have 
more fun), but somehow, I think a 

radio magazine ought to have a fold- 
out circuit. If you need to fill the 
other side of the centerfold, maybe a 
blond would be good fit would save 
me money, since I wouldn't have to 
buy the "other magazine"). 

Seriously, I enjoy 73 and hope you 
keep up the good work. It will pro- 
bably take me a month, though, to 
read your last issue, since I can't seem 
to get past the cover. 

Kent Cronyn WA2DRX 
' Tiffin OH 

f am a high school student and 
generally take 73 to school to read in 
my spare time. But if you insist on 
putting on cover pictures such as on 
the October and November issues you 
will end up thinning your youth ranks 
considerably. All kinds of rumors have 
been started about me and I was 
nearly expelled once before I could 
prove that it really is an amateur 
radio magazine* Believe me, people 
don't notice that the lady on the 
cover is holding a 2 meter rig. Please 
consider my plea before I end up in 
big trouble. 

Steve Antosh WB5BNM 
Shawnee OK 

A comment on the November 
issue . . . WOW! I haven't had a chance 
to get an actual count, but there must 
be more articles in this one issue than 
in an entire year of QST and CQ 
combined. Who wants 40 pages of 
operating news anyway? 

When I first saw the issue on my 
desk, I was sure you had finally 
published your cumulative index, or 
at least the entire FCC rules and Regs, 
Let's see CO top this one. 

Ron Warren WA2LPB 
Fredonia NY 

Thanks for the fine November 
issue. In fact, your covers the past few 
months have gotten my wife inter- 
ested in what I'm reading— and she 
might become a devotee if she sees 
enough of those type of covers; she 
doesn't want to let me read anything 
like that without her knowing whafs 
in the centerffold?}!! 

Wayne Heck WB9 HIM 

Ft 'Wayne IN 



My lawyer will be in touch with 
you. As you can see from the address, 
I am in the Folly Beach General 
Hospital with a hernia received trying 
to get the November issue of 73 out 
of its wrapper. 

(Seriously, am glad you stayed 
home awhile to mind the store. 
November issue is great. Always 
thought you could do it if you would 
stop running all over creation & 
attend to business. Am proud of you.) 

Ed Howell W4SOD 
Folly Beach General Hospital 

First my dog attacked my mailman, 
then you people at 73 sent this 
magazine (November 72), its size 
massive, gigantic and dynamic. This 
was the last straw for my trusting and 
loyal postal servant- Things here in 
Vancouver are about ready for the 
A.R.E.C. My dog and I thank you so 
much; keep it up! 

Jerry Dimmitt WA7MMD 
Vancouver WA 



I am sure the Wo mens Liberation 
Movement would dub you a "male 
chauvinist pig" as a result of your 
November cover. 

What disappoints me is that you 
have an excellent magazine and you 
really do not need bullshit like that to 
sell it; or is it possible that you realty 
do not know how good your publi- 
cation is? 

Mike Peters W9GHY 
Scandinavia Wl 

As spokesperson for the 73 
Women's Lib local chapter, I assure 
you Wayne was labeled a Male Chauvi- 
nist Pig long, long before the No- 
vember coven 

However — in all fairness and be- 
cause he is our boss — I make the 
point that the young lady willingly 
posed for the bullshit, so what does 
that make her? 

And you know^ most of you DO 
like the cover! 

Ruthmary Davis 
P.S* We don't know it is an excellent 
magazine because we aren't hams, but 
Wayne tells us it is. 

WA6TDD 

I suppose that the following is my 
own fault for not writing earlier and 
correcting it In your recent Repeater 
Listings and other ones around, they 
show WA6TDD in LA, as hasing an 
input of 147.420 MHz, with an out- 
put at 146.40 MHz. The inputs, of 
which there are two, is FM at 147,435 
MHz and AM at 147.405 MHz, I 
realize this is an odd-ball situation. 
TDD has been an AM open channel 
repeater on Mt. Wilson since Nov. '62. 
At the time we were at 145.425 MHz, 
with the AM input. The repeater was 
always very active except for approxi- 
mately one year's time when it was 
off the air for many reasons, none to 
do with amateur radio. Last April we 
added an FM input at 145.195 MHz, 



JANUARY 1973 



139 



These frequencies were picked due to 
intermodulation problems on Mt 
Wilson and at the same time to fit in 
between the other activites on two 
meters in the L.A. area. The activity 
was about equal between the two 
inputs, with both growing equally. 
When the docket came out it forced 
us to make a ddecision whether or not 
to abandon the AM or the FM input 
The "Frequency Coordinating" Com- 
mittee was not about to let TDD have 
two inputs. I can understand their 
thinking in part. But contrary to 
public belief there is a great deal of 
interest still in AM mobile operation. 
The people that operate the other 
repeaters that are FM only are not 
aware of the AM operation on the 
band. Besides the attitude that is 
shown by many that "Ancient Modu- 
lation" does not need a repeater, so 
TDD should only have one input and 
one output. This was put to the users 
of WA6TDD as to what they wanted 
to do. We decided that we would split 
the input channel and have both the 
AM and FM inputs. Both receivers 
have always had the overall band-pass 
to operate in this manner. We used to 
have a CD qroup operating about 15 
kHz off of the AM input without any 
interference. But it meant that the 
users of TDD had to either have good 
VFOs or accurate crystals. They got 
'em and used 'em. 



Burt I Werner K60QK 
Van NuysCA 



MINICOMPUTERS 

I just received and perused the Nov. 
issue of 73 and was utterly boggled by 
its size and content; I wish your 
advertisers and staff time would allow 
things to "get out of hand" like that a 
little more often! 

As a professional computer pro- 
grammer/sometime computer-main- 
tenance technician, and a reader of 73 
almost since its inception, I was parti- 
cularly delighted to read Jim 
Huffman's introduction to the design 
of minicomputers, I agree with his 
premise that increasing IC sophistica- 
tion and declining costs will very soon 
place home-brewed minis within the 
reach of most hams and experimen- 
ters, and it seems entirely appropriate 
(and perfectly in keeping with 73's 
tradition of publishing "meaty" con- 
struction projects using state-of-the- 
art circuitry months ahead of any 
other experimenters' magazine) that 
such an article should appear in 73, la 
fact, I would have been gravely dis^ 
appointed had "Popular Electronics 
gotten there ahead of youf 

In addition to concerning them- 
selves with the design and construc- 
tion of a mini computer, it seems to 
me that hams would do well to give 
some thought to the incorporation of 
minis into amateur communications 
systems; for example, for microwave 
enthusiasts to begin discussing and 
exploring the possibility of establish- 
ing amateur data-communications 
systems, not only between ground- 



based stations, but also with an eye 

toward the possibility of utilizing digi- 
tal-data transmission in future 
OSCAR-type projects* 

The Intel Corporation (3065 

Bowers Ave., Santa Clara CA 95051) 
manufactures a unusual MOS LSI 
chip, the 8008, which includes the 
entire "guts" (i.e., Arithmetic-Logical 
Unit, Instruction Decoder and Con 
trol, several internal registers, an 
IZO*bus buffer, and timing generator) 
of an 8-bit minicomputer in an 18-pin 
DIP; essentially it's a CPU on a-chip 
which need only be interfaced to a 
memory sub-system and some appro- 
priate I/O device-controllers to make a 
fairly sophisticated bus-oriented mini. 
The manufacturer publishes a data- 
booklet describing the 8008 and 
several other chips that make up its 
"MMCS8 Micro Computer Set" 
which presents an excellent descrip- 
tion of the operation of the CPU, how 
to incorporate it into a minicomputer, 
how to build a simple Teletype con- 
troller, and lots more. It's an excellent 
supplement to the Huffman article, 
and worth its weight in gold to 
would-be computer constructors. 

The chip itself, I'm told, costs 
about S200 for single quantities, 
which is outta sight for an IC, but 
dirt-cheap for a compiler. 

In summary, l see great room for 
experimentation by hams in the de- 
velopment and use of minicomputer 
systems, and I am pleased to see an 
mitial presentation of the subject in 



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140 



73 MAGAZINE 



73. I would like very much to en- 
courage readers with an interest in this 
field to get to work on concrete 
hardware development, and hopefully 
share their results with us via 73. 

Scott Marovich 
Chicago IL 



My article in the September issue. 
The CW Excavator" has an error that 
may cause some unsuspecting ex- 
perimenter to test his religion or 
maybe blow his top: on page 32 the 
equation for bandwidth and Ri are in 
error. The equations should be 



1 1 



Fh - 



Bl 



1 



u)tQi(Ci + C2) 



2fff?(Ci +C2) 



where u \ ■ 2n-f •) 
Ql=fj 

Bl 



Consequently the equation forband^ 
with should be 

Bi =o*ifiRi)Ci +C2» = 

27rfi(Ci +C2) 



The next to the last paragraph has a 
few words missing from the second 
sentence. The second sentence should 
read: The gain of the filter is about 
unity for 800 Hz, so there is little 
change when the filter is switched 
"in" or "out," but a comfortable level 
phone signal with the filter "out" 
disappears when the filter is switched 



in. 



For what it's worth, the article 
seems to have rung a bell for many of 
your readers, because I had letters 
from several asking about PC boards 
and IC substitutions a full two weeks 
before my subscription issue arrived, 

Parker R, Cojh* 
Amsterdam \ \ 



Didn't you come on a little bit too 
strong in your editorial "Incentives" 
in the Sept. issue of 73? I was forced 
to read your editorial twice, as I 
couldn't believe quite what had been 
written. 

I have often felt that the FCC 
examinations for the incentive licens- 
ing program were for the most part 
pretty fair. Some areas of a particular 
exam might possibly be rougher than 
others — dependent upon each indi- 
vidual's own preparation and interests. 
However, no portion of incentive li- 
censing should be condemned as you 
did so with the code. 

As the top grade within the ama- 
teur radio licensing structure, the Ex- 
tra Class license should require know- 
ledge and proficiency in the basic 
aspects of amateur radio operation — 
mainly, voice and code. 

Your editorial, as I read it again, 



didn't even mention that Extra Class 
license holders are granted additional 
allocations of our bands for CW opera- 
tion, not just the additional band- 
width for voice operation. Perhaps 
this is why the FCC has the 20.wpm 
code requirement in addition to the 
technical examination. 

If anyone has the right to complain, 
it should be the dedicated CW opera* 
tors who are required to pass the 
Advanced Class license examination in 
order to be eligible to sit for their 
Extra Class ticket, What does the CW 
operator do with additional phone 
privileges? This surely must seem un- 
fair to many. 

As amateur radio operators, we 
should, as we are now required by 
FCC, be virtually proficient in all 
aspects of amateur radio — not just in 
the area of our own personal interests. 
Nonetheless, the exams are there and 
we must live and abide by the rules, 
regulations, and requirements as im- 
posed by FCC until such time they are 
changed or amended — no matter 
what our personal feelings or interests 
tend to be. 

Mart- B. Millrr \\V8EV/K:JNAS 



73 Magazine is the best ham maga 
zine I have read — the ads are best 
because you have confidence in them. 

The "Petition to the FCC" by 
George W. Fyler W9JT, was the best I 
ever read- It is clear (to me) that he 
should be writing the FCC Rufes and 
Regulations for the FCC. Can we not 
petition the "President of the United 
States'? The FCC has too much 
power for such little action and con- 
sideration. I am a member of the 
ARRL but I feel they go along with 
the FCC. Anyway, I worked for the 
Federal Government for 32 years. 
"Nuf" said. 

I will help any way I can in the 
above Petition, but? 

Bill WB4SNK 
Jacksonville FL 



K4YKB and his "TEN-ROGER" 
dissertation (Nov. 73) sent me into 
hysteria! Paul Rinaldo of McLean VA 
has run-off one of the most ungodly 
truth filled articles I've had the pleas- 
ure of digesting in a great long time. 

It is my misfortune to be among 
the fraternity of the few remaining 
"legal" CBers (KFA6162) that date 
back to about 1959 when the band 
was being used for the purpose inten- 
ded; and now it's a #*+%&@$%S mess 
to say the least. 

It was reported that one of the 
local LA. CBers purchased for cash 
money across the counter (name of 
store undisclosed) one of HENRY 
RADIO'S hard punching KW "after- 
burners" - that will give you some 
idea of what we might expect on the 
proposed "CB 220 MHz" deal. 

So, come on hams - get your 220 
gear on and shoot the Federal Candy 



Company some of that there "wall- 
paper" protesting the El A propo* 
sals- TEN-ROGER yaall? 

Bill Ford WB6SNLJ/KFA6I62 

Pomona CA 

I saw your editorial regarding the 
elimination of CW as a requirement 
for the Extra Class license and 
thought I'd give you a CW operator's 
point of view. 

Since you do not operate CW, the 
only band segments you have lost are 
a small section of 75 and 15 meters. 
But as a General Class licensee and a 
CW operator, I have lost the choicest 
25 kHz segments from four bands. 
The 20 wpm code exam is nothing for 
me, but why should I have to learn a 
lot about single sideband just to crank 
my vfo down to the bottom 25 kHz 
of each band? I feel that the only 
requirement to operate in the Extra 
Class CW bands should be the code 
exam. 

When it comes time to renew my 
license, at least I can state with a clear 
conscience that I still have the mini- 
mum code speed required for my class 
of license, I wonder how many of the 
"phone only" operators can do the 
same* 

Bnire Koehler WR0BCT 

(Most, I think, for I notice my code 
speed does not change much even when 
I don't use it for a year or so. It only 
takes a couple minutes to get back in 
the swing of it Wayne J 



I am a CB'er and am trying to get 
involved into this 220 bit, 

I would like to say right here and 
now, I feel the amateurs are entiled to 
220, and the fathead who thought of 
using 220 for "CB" should be stood 
up against a wall and shot! 

Yes, CB is crowded and noisy r but 
if the money hungry idiots at this 
El A, a reactionary outfit, would just 
get it through their fat heads, they'd 
realize there are plenty other fre- 
quency ranges available, not neces- 
sarily amateur radio bands, but possib- 
ly the government would give up one 
of their sacred bands. 

Then there is the possibility thatCB 
could go FM (no offense intended), 
and possibly some other modes such 
as, preferably, RTTY. 

You all think I may have a wild 
imagination, but I'm not very inter- 
ested in amateur radio (sorry about 
that!), but experimentation of CB 
with such modes would be most inter- 
esting for those like me. 

Enclosed is a money order for one 
of your "220 use it or lose it" shirts. 

J iiii Buscher III 
Arlington VA 



Immediately upon reading Cliff 
Klinert's excellent article on solid- 
state ID in the October issue, I set 
forth to produce a unit for our new 
repeater here in IMorwalk, Conn., 



JANUARY 1973 



141 



Y/213SD/1 continued 

MAY WE GET 11 METERS BACK? 

It's pretty definite now: the Cra^y 
Bunch wi be coming to 220 
W\Hi - that's the bunch now filling up 
the eleven meter band w»th illegal 
power - illegal antennas - iJlegal 
towers — illegal VFOs - iflegdl skip 
contacts - illegal hamming — illegal 
calf signs — unlicensed operation — 
profanity and obscene language — 
widespread use for crime communi 
cations, which is illegal — and so oa 

While the amateur frequencies that 
are going to be turned over to this 
bunch of . . . unusual people , . . are 
probably the most valuable and need- 
ed ham channels presently not in use, 
there are some shreds of silver lining 
to the situation. If FM continues to 
grow as it has during the last two 
years it won't be long before the 
pinch for repeater channels will be 
painful and the realization will come 
that amateur radio goofed and goofed 
badly when it did not set up a lobby 
in Washington to protect its turf. 

Now, for the bright side. When the 
CBers are scraped off the 27 MHz 
band and shoved down onto 220 
MHz, it seems possible that this band 
may again be opened for amateur use. 
Since the neighboring ten meter band 
is far from bustling, even during peak 
periods, 11 meters could languish as it 
d*d in the *50s unless something extra 
is allowed. Perhaps this might be the 



LETTERS continued 

W1WHZ. I got about fifteen minutes 
down the line, when I realized that alt I 
of us here in "1"-Land, and I'm sure, 
many others, have a problem with 
overloading the eight-bit capacity of 

the 7430 IC's. Cliff does spell out a 
rememdy for this in his article using 
an inversion process and some addi- 
tional 7400 r s. While this will certainly 
work, it does involve some more 
complication and cost and it reduces 
the ability to construct a "universal" 
ID unit which can be easily changed 
to a new call sign if necessary. This 
will be important in view of the new 
repeater rules which will require all of 
us to change calls in the near future. 
I think I have a simple solution to 
the problem which may be of aid to 
those of your readers who find them- 
selves in this same situation, The I 
answer, as simple as it may sound, is 
to allow six units for letter spacing 
rather than five. This will allow 
enough room for almost all combina- 
tions of characters, with the exception 
of the poor guy who has a zero in his 
prefix. There does not seem to be a 
simple answer for him other than the 
inversion technique, or possibly allow- 
ing additional bit spacing, 

Will jam ||. kbiirn. Jr. W UOPR 

W>lporl CT 



band where the FCC would permit 
longdistance repeaters. 

DXing repeaters would be fun, and 
if we could tie them into our VHF 
and UHF repeaters with crossband 
links, they could be extreme Jy valu- 
able for emergency purposes. There is 
no real shortage of frequencies on the 
ten meter band for this, b*<t the FCC 
has conjured up some sort of imagin- 
ary congestion that might take place 
twenty years from now and come 
down hard against ten meter repeat- 
ers. Perhaps the wide open spaces of 
1 1 meters would counter this think- 
ing, 

HOW WAS 220 MHz LOST? 

The FCC bowed to pressure from 
congress via the well-heeled El A 
Washington lobby. Anyone interested 
in the inside story on how this situa- 
tion works has but to read the current 
best seller, "Who Runs Congress/* 
This is the SI. 95 Bantam Books 
ZY7701 Ralph Nader congress project 
report. 

Since it is estimated that over 90% 
of the prospective sales of 220 MHz 
equipment will be of Japanese manu- 
facturer; one wonders just who is 
actually bankrolling the El A push for 
the band. Ah, so? The fact is that the 
new band will make millions of dollars 
for Japan — perhaps up to SI 00 mil- 
lion per year. They'd have to be daffy 
not to invest a few million in a 
proposition like that - and no one has 
accused the Japanese of being daffy 
yet. 

The Nader report will give you the 
lowdown on how money passes from 
interested parties through lobbyists to 
congress, thus buying little baubles 
like a meg at 220 MHz for the Crazies. 

LESSON LEARNED 

Readers of the aforementioned 
Nader congress report wil find that 
the suggestions made in 73 for hams 
to have a Washington lobby are 
backed up completely. Without such a 
lobby the amateur frequencies are 
wide open for any group to grab. Only 
the complete lack of any lobby in 
Washington for amateur radio made 
this theft of ham frequencies possible. 
You might ask your ARRL director to 
explain again why ARRL has no 
lobby to represent us in Washington. 
This has been explained \n the 73 
pages many times, but is an un 
pleasant situation and we tend to 
forget about it. 

We need a group to set up a 
lobby — we need it desperately — 
where are you — were are you? 

CAN HAMS GET SOME TOO? 

Any enterprising ham should be 
able to do very well as soon as the 



new band is announced. Nice Japanese 
rigs will be available from Henry, 
Standard, and others such as Drake, 
SBE, Swan, etc. Even crystals will be 
available from Japan for a fraction of 
the cost of U.S. crystals. Antennas 
will come pouring in from Japan too. 
If you want to get into a good big 
business you can gel yourself set up as 
a dealer and start installing these CB 
stations and servicing them. Any FMer 
has the knowledge to set these things 
up and keep them going. 

If this band goes the way of 11 
meters — and there is no reason what- 
ever to expect anything different, you 
may be into selling towers, high 
powered amplifiers - the works. 
Watch for some interesting new ampli- 
fiers for the band too — several manu- 
facturers are ready to announce some 
250 and 500 watt mobile solid state 
amplifiers - and one is hard at work 
on a 1000 watt mobile amplifier for 
the bandl 

CBers found that once they are on 
a band in large numbers there is 
nothing the FCC can do to police the 
situation — so anything goes, No li- 
censes are needed, obviously, A chap 
with a base station might worry a bit 
if the FCC starts a cleanup in his 
area — but these things never last long 
and it is always back to business as 
usual in a few weeks at the worst — 
and of course there is virtually no way 
for the FCC to catch a mobile station, 
so mobile ops don't even have to 
worry when the FCC is right in town. 

Another good business may turn 
out to be setting up remote base 
stations for the new CB band. CBers 
like to work DX and get good wide 
coverage — and this means a mountain 
or tall building. Few CBers will be 
able to hook up the remote control 
circuits needed for a good remote base 
station — so there is a fine oppor- 
tunity for experienced amateurs. 

Most of the CB rigs will probably 
be either crystal controlled or synthe- 
sized — which means that there will be 
a possible market for VFO's for work- 
ing in between the 25 kHz channels. 

Wayne 



TIQN i 

Code) I i-!!r i'( 



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IcIUaf! 
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ijutili <h 
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immrdi-tli'lt i li> i> mnii'i tin 



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nit , tlplr,£ll' i .. i i 

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i h ■ - ■, it 1 1 1 1 v- : i \ t he p u bll*hr r* \ N ■ « 1 prim- 
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br i Mttrrv- -*b KH nil*.* 1js» 

Grn ' '( ft-USJt S. Kn---+Ti bond* 

n>ilc!if- iikr>rli- lid lit -ft J* Id^rv MwTilftf, ■•! bnldmr 1 

llicT u-r ii 11- 

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t!-4fini u*»^<*hnf 12 rr>"nih -Ji-*.™ ht an 
mI iui^i iUh puMbltri! ct- fill nc i.. 

S; i ■ If \oi y X . * ~! 

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"l-iJl i'l li i 



142 



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JANUARY 1973 



143 



Caveat 



***-*.>-♦:♦:♦>:♦:♦:♦:♦:♦:• 



Pnce - S2 per 25 words for non -commercial 
flds, $ TO per 25 words for business ventures No 
display ads or agency discount Include your 
check with order, 

Deadline for ads is the 1st of the month two 
months prior to publication For example 
January 1st is the deadline for the Mart;h issue 
which will be mailed on the lOrh of February. 

Type copy Phrase and punctuate exactly as 
you wish it to appear No ail-capital ads 

We wilf be the judge of Suitability of ads Our 
responsibility for errors extends only to print- 
ing a correct ad in a later issue. 

For Si extra we can maintain a reply bo* for 
you. 

We c anno t check into each advertiser, so Caveat 
Emptor . . 

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same day. Write today for our low 
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R.R, 25, Box 403, Terre Haute, 
Indiana 47802. 

SALE: T14/TRC1 BOW F.M Trans- 
mitter and R19/TRCT Receiver 
w/C.O.R„ 70-100MC, 110V AC, with 
schematics. Original Army crates- S45 
ea. S75 pr. Shipping Collect, LaBella, 
1100 Clove Rd,, Staten Island NY 
10301. 

PILOTS/HAMS . , , FOR SALE, 
CHEROKEE 140 (1968) WITH 
GENAVE 600 NAV COM, GLIDE 
SLOPE, ADF, TRANSPONDER, 2ND 
VOR, MARKER BEACON RX, 2 
AXIS AUTO-PILOT. PLUS 2 ME- 
TERS FM AND 6 METERS FM. 
CONTACT KEITH W7DXX/1 AT 73. 
(603-924-3873) 



FOR SALE Regency HR6 and 

HR2MS still in unopened boxes. 
Brand New! Swan 50QCX, power sup- 
ply (ac), External VFO, Mark II 
Linear, Box 3432, c/o 73 Magazine, 
Peterborough, N.H. 

BEING DRAFTED. Anyone want a 
good deal? Mint Standard SRC 826M 
$250. Excellent condition. Simpson 
Model B S200. Mini -vox IVL Walkie- 
talkie, Make offer. Box 3246, 73 
Magazine. 

ARTHRITIS FORCES SALE of GLB 

2 meter synthesizer, set up for use 
with any rig SI 50. Digital "logiclock" 
$75. Box 1303, 73 Magazine. 



MODERNIZE FOR PEANUTS! 
Frame & display QSL's with 20 poc- 
ket plactic holders. Two for $1.00, 
seven for $3,00. Prepaid, guaranteed. 
Universally used and approved. Order 
Now. TEPABCO, Box 198S, Gallatin, 
Tennessee 37066. 

CLEANING SMALL APARTMENT, 
220 FM 5w xmtr $15; 2M FM talky 
250mw tuneable rec.S75; T 44, rec on 
439.25 atv 12v S25; VI D I CON 7038 
w/focus & deflection coits S20; Cas- 
sette recorder $10; 220FM pwr amp 
xistor 6w (QST July 72) $15; APR-4 
tuning head 300-1000 mhz $10; FM 
monitor Hi&low w/squelch S30; 
12vdc 100 amp alt. $20; 10 meter PA 
3w input 60 w out S30; 2 meter PA 
300w $75; 3BP1 scope foundation 
$12; and still more. SASE please, 555 
Patten Ave., Apt. 38- B, Long Branch, 
N.J. 07740. Want URC4&11 price, 
condition, trade? 

TTY EQUIP. 15-19 printers, 14 TDs, 
tape perfs., power supplies, tables, 
tape, paper, audio converter. GST's 
1946 thru 1970. Make offer. W6NQE 
707-822-5500. 



FOR SALE: Gonset II - $50-00; 
Gonset III - 6 meter - $75.00; Gonset 
IV - $90.00; Poly Comm IV * 
SI 50.00; Gonset G-28, 10 meter tran- 
sceiver - S 155.00; Clegg 22er - 
$120.00; Tektronix AC Current Probe 
- $35,00; Norelco VTR - $300.00. 
WB2GKF Stan Nazimek, 506 Mount 
Prospect Avenue; Clifton, New Jersey 
07012. 

CANADIAN DEAL! Selling Heathkit 
DX-60A $60. HR-10 receiver with 
voltage regulation, modified Pre-amp 
S50. Good Condition! Want HW32, 
HW12, Ian Baines, 1675 Wedmore- 
way, Mississauga, Ontario, 



TEMPO FMP transceiver with TPL 
252-A2 25w Amp. and Hustler 
BBLT-155 Ant. S230 takes all. Russ 
Appleyard WA2MHY/3, 3600 Chest- 
nut St., A121, Philadelphia, Pa. 
19104.315-349-7489. 

LATEST GOODIES: TECHNICAL 
MATE R IE L CORPORATION 
MODEL TRC-500 Antenna Couplers. 
Match 70 ohms to 150, 300, or 600 
ohms over 2-30 MHz region with NO 
tuning. In weatherproof box, like 
new, original MIL packing with data 
sheet and mounting hardware. Cost 
S520 originally, now only $27.50. 
AT-741/A Aircraft Antenna, works up 
to 1220 MHz like new, $5.00, HQ-170 
$120.00, TS-497B $150.00, SASE for 
list. All FOB Richard Solomon, Five 
Cherry Street, Lexington, Massachu- 
setts 02173. 

OA442-/GR 2 METER amplifier 500 
watts out $350, Lamp kin 105B freq, 
meter & PPM excellent condition 
SI 50. Douglas Barker, P.O. Box 182, 
Eatonton, Ga. 31024. 



SELL: SWAN TV-2B-2 meter 240 
watts CW and SSB transverter with 14 
MHz input. Extra crystals. $200, Cliff 
Dweller 80 and 40 meter dtpole with 
3 motors S75. Tom Carter W1BHZ, 
19 Webb Gir., Moncore, Conn. 06497. 

COMMUNICATIONS TECHNICIAN 
seeks overseas employment. First 
Phone with Radar. Amateur Extra 
license. Experience: HF. VHF 
Communications; Antennas; Aircraft 
Navigation; Test Equipment 
maintenance, calibration. Also 
Technical Writing, Drafting, 
Machinist, Management experience. 
Age 27. Seek Challenging Job with 
Responsibility. For Resume write; 
John Brosnahan K0UTX, P.O. Box 
1716, Boulder, Colo, 80302. 



YOUR CALL LETTERS, Two sets, 
for windshield and rear glass. Smart 

white letters with red outline. Easily 
installed, pressure sensitive decals. 
$1.00, postage paid, anywhere, Satis- 
faction guaranteed. Lake Jordan 
Artists, Slapout AL 36092. 

WANTED: OLD RADIO TRANS- 
CRIPTION DISCS. Any size or speed. 
Send list and details to Larry Kiner, 
W7FIZ, 7554 132nd Ave, N.E.. 
Kirkland, Wash. 98033, 

FOR SALE . . . Signal One CX7 A 
with matching speaker and both CW 
fitters. Brand new at only $1500.00. 
Box 442, 73 Magazine, 

WAR SURPLUS FOR SALE - 4 
70VA tubes, type 701 -A, 5 KW peak, 
S25 ea, 10 828 tubes, 250 watt, $2.00 
ea. 1 250 MM F Variable Condenser, 
20 K peak, nearly 1 foot long, S1O.00. 
M.A. O'Bradovtck W6TG, 19323 
Lanark St., Reseda CA 91335. 

8 EL. 6M. BEAMS. A/S HM 171 Reg. 
List $109.95. Close out price $29,95. 
F.O.B, Cleveland, Ohio. Communica- 
tion World, 47B8 State Road, 
Cleveland, Ohio 44109, 

DIVORCE and alimony dictates that I 
sell the following fast: CLEGG 
FM-27A, S300. Pair of Standard 146, 
$210 ea. First check takes each item. 
All like new condx. Box 2611, 73 
Magazine. 

"22nd ANNUAL Dayton Hamvention 
will be held on April 28, 1973 at 
Wampler's Dayton Hara Arena, Tech- 
nical sessions, exhibits, hidden trans- 
mitter hunt, flea market, and special 
program for the XYL. For info write 
Dayton Hamvention, Dept. 7, Box 44, 
Dayton, Ohio 45401." 

2-WAY TECHNICIAN or SERVICE 
MANAGER, experienced, needed by 
expanding 2-way service organization 
in Dallas, Texas, Send resume to RAM 
Broadcasting, Attention Cecil White, 
Post Office Box 10373, Dallas, Texas 
75207. 



144 



73 MAGAZINE 



65.00 
. 39.00 
. 32.50 
. 49 50 

. 49.50 



SLEP'S SPECIALS 
RECEIVERS - TRANSMITTERS - TEST EQUIPMENT 

COLLINS R-3S9/URR VLF RECEIVER, tunes 15 kHz to 1500 kHz. digital read-out. VLF version of R 390/URR, Ihe 

best, I 9 11 rack mouni , . >..-■•« . . $450.00 

COLLINS R-390/URR. tunes 500 kHz thru 30.5 MHz, digital tuning AM/t W/FSK, SSB W rack mount .... 550.00 

RCA AN/SRR-13 RECEIVER, tuneable 4 thru 32 MHz AM/CW/FSK. J 15V/60 Hz, used by the Navy _ . 165.00 

COLLINS 5 IM RECEIVER tunes 500 kHz thru 30 MHz, has 3.1 and 6 kHz mechanical filters, 19"' rack mount A fine 
communication receiver ...... , . . . ...-•..♦■ . 550.00 

R-13B 10H 135 MHz TUNEABLE RECEIVER, late VHF version of the famous Command Receiver, ideal for 
airport/aircraft Listening or convert to 2 meters. Has 12 vol I tubes . . . 16.50 

HAMM A R LUND SP-600JX. tunes 540 kHz thru 54 MHz tn 6 hands 19" rack mount 285.00 

AN/URR 13 RECEIVERS, tuneable UHF 225-400 MHz, used to monitor military and astronaut frequencies, AM/fW, 
I I5V/60 Hz ; .„ 85,00 

BG348, a great receiver for AM/CW and manne VLF/HF work, unmodified original 28VP/S, easy to convert for 
!2VDCor 1 15/60 Hz, tunes 200-500 kHz and 1.5 to 18 MHz ... - 

HP-430C RF POWER METER, 19" rack mount, reads directly in DBM or MW. Perfect for any shop or lab 

RT-67/GRC FM ARMY JEEP TRANSCEIVER tuneable 27.0 to 3SS MHz 16 watts .... 

R-278/GRG27 RECEIVER 225 to 400 MHz 10 preset channels AM. 1750 selected channels. I I5V/220VAC 

T-217yGRC-27 TRANSMITTER 225 to 400 MHz 100 watts, 1750 selected channels AM/MCW I 15/220VAC . 

MEM 29/GRC-27 MODULATOR, goes with T-2 1 7/GRC 27 mw * . ........ 39 50 

TV-2/U TUBE TESTER, mutual conductance checks old and late type receivers, transmitters and sub-min type. 
Complete with roll chart and book. Late Viet Nam vintage, the best, cost Govt. $960.00 ...*....*. 65,00 

TS413/U SIGNAL GENERATOR 75 kHz to 40 MHz in 6 bands, precise calibration from 1 MHz crystal oscillator, has 
% modulation meter CW. or AM 400/1000 CPS variable 0- 50% and RF level meter LOV. Ideal for amateur, marine, 
aircraft and hobbyist for IF and receiver-transmitter alignment or development work . , . . , . . 89.50 

SG*66'ARM-5 OMNI SIGNAL GENERATOR, military version of ARC HI 4 FAA approved for aircraft radio 
shops . . 550.00 

TS-382/U AUDIO OSCILLATOR, 0-200 kHz with 60 and 400 cycle reed frequency meter check point. A fine lab 
instrument . . 79.50 

SG-299/U SQUARE WAVE GENERATOR, a wide range I Hz to I MHz continuous coverage, use with any oscilloscope 
to determine frequency response and phase shift characteristics of video and audio amplifiers, military version of 

HP-21 I A i .'.... - 39.50 

TS-505D/U VTVM 0-25OVAC, 0- IO00VDC, 0-1000M ohm resistance measurements. AC frequency response, 30 
Hz 500 MHz, high input impedance, portable ruggedized construction complete with probe, late military vintage 45.00 

AN/PRS-3 MINE DETECTING set in shipping case. A popular unil used for locating relics and lost items. Can be used 
around salt water and iron soO. Gives meter reading and tune. Takes standard 1 ViV and 45V batteries, not supplied, 
original Govt cost $800. GO, have fun for only . . . *. * . * * ...*,............,....... , 24,50 

COLLINS RT-349/ARC-55 UHF TRANSCEIVER 225-400 MHz. Would make a Tine 220 MHz amateur rig 65,00 

COLLINS I8S-4 TRANSCEIVER, 10 channel crystal controlled from 2 to 1ft MHz, 100 watts output, AM/CW. 811 
modulators to 813 fine, operated from 28V DC dynamotor included or convert to AC. Ideal for Novice, MARS, RTTY t 
marine, or aircraft, like military version of ART- 13 . . , , . 47.50 

BALLANTINE 300 AC VTVM, 10 Hz to 150 kHz range, IMV to 100 volts in 5 ranges, logarithmic scale 1-10 DB, 

accuracy 7%, A fine insl rumen L ,-.»'.•#'.>-./ . v . ...-..* • * . . > 29.50 

CARTER ROTARY CONVERTER. 28VDC input, with 1 1 5V/60 Hz output at 2.3 amps. Can be portable hand carry, 
ideal for campers, boats, electric tools, small TV's, ham field trips, emergency, AC power, forkiifts, Govt, cost 

iff T \J^ / u. \J\J 4frt*t>ft**4fti***i ■■*""""-" ■ «■■■■■■■■■■ »■■■■■■■■■■* ^ ■■■■■■■ a ■ | ■ # *| .B.PP1. k I I 'l I-' i I I, i t t i !l « .^ p'ft.f i t*| ' * i *-* V 

19" OPEN FRAME 6W FT. HEAVY DUTY RACK drilled to mount any military 19" equipment, Shipped knocked 
down with all hardware. Shipping weight 1 00 lbs, , , , , , , . , , 37.50 

CV-1758/URR TMC MODEL MSR 9 SSB CONVERTER. Designed for the detection of single side band signals, this 
MSR {Mode Selector Receiving* will also improve reception of CW. MCW, AM and l"SK with any degree of carrier 
insertion. Works with any receiver having 455KC IF. Size L9"W x 5W"H x 13 s /j" deep, weight 26 bis, Late Viet Nam 
version of the famous CV-59 1 A/URR converter, price , 1 25.00 

ATTENTION: LINEAR AMPLIFIER BUILDERS 

JENNINGS UCSL 1 0-1 000M MFD VACUUM VARIABLE CAPACITOR, rated 5000 volts with gear drive train and 
mounting bracket. Has shaft and gearing for manual tuning, size 8!£"L x 3"W x 3 ,f H, Popular for linear building 29.50 

30 AMP GROUNDED GRID FILAMENT CHOKE, bifilar type '//* x 7ft" long, use with pair of 4-250A, 4-400 A, 
3-400Z. 3-500Z, 8 1 3S or single 4-1000A, 3-1 000Z ,....-.... ................ 8.50 

NEW FACTORY EIMAC YELLOW BOXED TUBES FACTORY GUARANTEED ■, . . 

EIMAC 3-400Z $37.00: 3-500Z $37.00; 3-1000Z $88.00; 4-400A S57.00; 4^tO0C $64.50: 4-1000A S 140.00; 
4CXI000A S200.00;4XI50A 523.00; 4CX250B S34.00: 4CS250K $76.00; 4CS250R S48.00; PL- 172/8295 A S210.00; 
PL-175A $93,50. 

EIMAC SK-510 socket 3-I00OZ, 4-100GA . ......... $10.50 

EIMAC SK-516 chimney 3-I00CA ,,.... ,-*. . 12.50 

EIMAC SK-506 chimney 4-JOOOA . 12.50 

EIMAC SK*4?G socket 3-4002, 3-SOOZ . . . - - : 10.50 

EIMAC SK-4I6 chimney 3-400Z . . . - 7,00 

EIMAC SK*406 chimney 3-500Z - 7.00 

EIMAC SK-650 socket 4X1 50A, 4C.X250, no screen by-pass ,.,..- 13.00 

EIMAC SK-620 socket 4X150, 4CX250, has screen by-pass • 15.50 

EIMAC SK-626 chimney for SK-650. SK-620 , - - - - 2*25 

EIMAC SK-636B chimney, includes anode clamp for SK-650, SK-620 14,50 

EJM AC SK-800B socket 4CX1000A. 4CX1500B , - - - _ 74.50 

. ♦......- - 17.50 

1 30 
3 10 



EIMAC SK-806 chimney SK-800B 

EIMAC HR 6 heat dissipating plate cap for 4-65 A, 4-400, 3-500Z etc. 
EIMAC HR-8 heat dissipating plate cap, for 4- 1 000 A. 3-IO00Z ..*„-. 
. . „ , , , , Send Needs for Oiher Eimae Tubes and Sockets. 
S72B/T160L TUBES BY CETRON, new factory boxed ... 



\» t m 



. 18.50 



All mail or phone orders shipped promptly, F.O,B. EUenton, Florida, Satisfaction guaranteed or money 
refunded. Starting our 17th year serving customers world-wide. We thank-you. 



mummtm. 



2412 NORTH HIGHWAY 301, ELLENTON, FL 



33532 



146 



73 MAGAZINE 



s 



X 



x 



X 



X 



X 



X 
X 



X 

X 



X 

X 



X 
X 



X 
X 



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XK 



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JANUARY SPECIALS 






arm 

COMMUNICATIONS 




COMTRON Model 960A DC Mobile Unit New as-is. Complete $129.00 

This unit is all solid state except the driver and final output tubes which are instant 
heating. Unit is 15QMHz Front Mount type 30Watts. Two channel deck included 

! \j- %-t # 




^'X^^lto^lM 



MOTOROLA Model X53GKT mobile unit with accessories 

This unit has two 60Watt Hi Band Xmtrs and one 
multi-channel operation. Transistor Powered. 



$139.00 

Hi Band Receiver for 




GENE RAL ELECTRIC Model ME33 Mobile Unit with ace $89.00 

This radio is vibrator powered, will operate from 6 or 12VDC on the Two Meter 
Band with 30 Watts out. 



Ma 



(inn COMMUNICATIONS & ELECTRONICS, INC. 

28710 Canwood Road 
Drawer M Agoura CA 91301 

(213) 889-6666 



1 



x 

X 



x 



x 

X 



X 
X 



id 
X 



i 



X 
X 



i 

X 



£ 

X 



2837 North 24th Street 
Phoenix, Ariz 85008 
(602) 955-4570 



x 
x 



v 

tx 



JANUARY 1973 



145 



! 



SOLA CONSTANT VOLTAGE HARMONIC 
NEUTRALIZED TRANSFORMERS 

INPUT 110 or 220 
OUTPUT ITS • ._ 

RATING 250 VA 2 12 9rn P % 

ELIMINATE BROWN OUTS 

PRICE: $19.95 

TRANSFORMERS STANCOR 
F610 6.3VCT <P10 amp* 115V INPUT 60 cy. 

SHIP, WT 5# PRICE: $2 95 

DIODES 

1 imp. BULLET TYPE w/ SILVER LEADS 600 P. IV. 
PRICE: 10/$ 100 or 110/$ 10.00 

METERS PANEL TYPE WESTON MODEL 1238 
0—500 microampi full scale calibrated .005 to 500 
roan tgern/ hour i 270 degree scale, appro*. 3" die, 
excel lent for vwavemeter etc. New end in original boxes, 

PFUCE $1.95 ea or 3/S5 00 

#360 TEKTRONIX WAVE FORM INDICATOR 

bandwidth DC to 500 KC Sensitivity .05/DIV. 

50V/DIV. waveforms required for nor. deflection. 

Sire: 4" x 12" x 14" 

#160A regulated power supply for above indicator. 

Size: 4 ' h 12" x 14" 

+FI62 wave form generator for above indicator. 

Sire: 4" x 12" x 6" 

SPECIAL PRICE FOR ALL 3 UNITS 
SHIP, WT. 35# PRICE: $99 95 

MINOR REPAIRS NEEDED 

T.S 323/U R 

ALL MAV£ CAL. BOOKS BARGAIN NOT JUN K 

PRtCE: $24.95 

UTC TYPE TGR 

TELEGRAPH TONE FILTERS. WE START AT 765 

A GO TO 2806. HAVING THEM IN 170 CYCLES 

STEP, 

LIMITED QUANTITY PRICE: $7.95 63. 2/$1 5.00 



CAPACITORS 



65,000 MFD 5V 
20,000 MFD 30V 
40,000 MFD 10V 



PRICE: 3/$1 ,00 or 10/S3.00 



MODIFICATION KIT 110896 TO PROVIDE OPERA 
TION OF MODEL 14 TO <fi& 100 wpm FOR GOV 
ERNED MOTORS, NEW. PRICE: $5.95 

R 11A LOW FREQ. RECEIVER 190-550 KC 

modern Q 5 'ex. 

SHIP. WT, S# PRICE: $4.95 Of 2/S8.O0 



#R 48 REC. freq. 230-250 mc 
SHIP. WT. 45 



r 



WT2B2 D/GR tran*. freq. 225-400 mc. 
SHIP. WT. 150# 



PRICE: $24.95 
PRICE: $39.90 



DIGITAL READOUT SET 

Make your own counter, frequency meter, 
digital voltmeter, readouts, etc. 
Kit includes — 

6 nixies with 6 sockets 

1 transformer 

1 P/S board w/socket 

PRICE: $T2.95, 2/S2O.O0 

GIANT ALPHA NUMERIC TUBE READOUT 
Price: $1.25, 5/S5.00 Sockets: 5/S1.00 



METERS 



0-500V DC 3K " NEW 
0-1.5 MA DC 3H" NEW 
0-10V DC 3V&" NEW 



PRICE: $1 95 or 3/S5.00 
PRICE: $1.95 or 3/$5 OO 
PRICE: $195 or 3/S5.00 



OPEN FRAMEPLATE TRANSFORMERS 
INPUT 105, 110, 115, 120. 125 VOLTS - 60c v i 
SECONDARY 3200 VCT ♦ 1 #mp, 
SIZE 914" m lOH'" m 10V NEW 

Ship WT 100# PRICE $39.95 

TORCH D TRANSFORMERS 

MOST VERSATILE WE EVER HAD 
3* RD 3' M 

WT 3# 

4 14 V INPUT WINDINGS 

45V FEEDBACK WINDINGS 

2 333V - 1/2 amp. WINDINGS 

2 167V - 1/2 amp. WINDINGS 
WILL SUPPLY 10O0V# 1/2 amp. 
CAN USE ANY COMBINATIONS OF ABOVE. 
SHIP. WT. 5# PRlCEr $5.95 or 2/10.00 



UTC-DOT-7 
200K-PRL 
1 K-SEC . 



PRICE: $1 50 ea or 4/$5 00 



UTC- DOT 9 
10KPRI. 



6O0 OHMS C.T. SECONDARY 

PRICE: $1.00 ea, or 3/$2.50 



TRANSFORMERS 

115V INPUT 

10 or 20 V.CJ OUTPUT @ 1/2 amp. 

SHIP. WT. 1%# PRICE $1.50 ea. or 3/$SOO 



12" CONCRAC MONITOR CKD-14SP HI IMP, 
INPUT 75 OHMS VIDEO INPUT SHIP WT60# 



ROTRON FANS 

SAUCER FANS 

280 CFM T DIA. x 2ft" DEEP 1 15V-50-60 cy. 

PRICE:$4.9&EA. 



FEATHER FANS 
270 CFM 7 M DIA. 2-7/16* DEEP 



PRICE: $ 4.95 



WINTRONIX MODEL 850 INDUCED WAVE FORM 
ANALYZER. Thii unit, in conjunction with your 
present oecilloacope, permit! you to view wave formi 
In the rmngm from audio thru MHz without any direct 
connection. The probe ti limply placed over the tube 
in qu eat ion end the wave form, la diep rayed on the 
oacilloacopa. It may alao be uted ea a high gain 
amplifier to increaee 'ecope aanmiiivity. Excellent lor 
TV., radio, amplifier, end tranamitter repair and 
maintenance. Brand new, -with probe. 
SHIP WT. 13# PRICE: $19 95 ea. 

AMPEX RF 3 
COMPLETE MEMORY - RACK MOUNTED IN CAB 
iNET. INCLUDES POWER SUPPLY - SENSE 
AMPS - READ &t WRITE CIRCUITS. ALL l-C LIKE 

NEW, 

ship. wt. 2QO# PRICE ON REQUEST 

MEMORY CORE STACKS 
32K 
42K 
SHIP. WT. 100# 



PRICE $49.50 



IC BOARDS 

962 936 

946 933 

948 951 

EACH BOARD HAS 3 OF ONE TYPE OF ABOVE 

PRICE: $2,00 ea. or 3/S5 0O 



IC BOARDS 

15 IC ON BOAR0 TYPE 90O - 914 & 923 

PRICE: $2.00 ea. or 3/$ 5,00 

14 PIN DUAL INLINE 
IC SOCKETS GOLD PLATED CONTACTS. 

PRICE : 50* ea. or 5/52,00 



ALL PRICES ARE F.O.B. OUR WAREHOUSE, PHILADELPHIA, PA. ALL MERCHANDISE 
DESCRIBED ACCURATELY TO THE BEST OF OUR KNOWLEDGE. YOUR PURCHASE MONEY 
REFUNDED IF NOT SATISFIED. TERMS ARE CASH. MIN, ORDER $5.00. ALL MERCHANDISE 
SUBJECT TO PRIOR SALE, RFE- REMOVED FROM EQUIPMENT. 



1206 South Napa Street 
215-468-7891 



SE1KTR0N ICS 



Philadelphia PA 19146 
215-468-4645 



JANUARY 1973 



147 




DuPage FM 



a 



A^^lT YEARS SPECIAL 




RCA CMF 55 MOBILE UNITS 
50 WATTS OUTPUT 25-54 MC 

With Accessories 

NARROW BAND TRANSMITTER AND RECEIVER 



These units have just been removed from commer- 
cial service and are clean and in good condition. 



Prices 



1 to 5 Units $50,00 

5 to 10 Units $45.00 

10 or More $40,00 



each 
each 
each 



Terms; All equipment sold as is. Money back if returned prepaid and unmodified 
within five days of receipt, Illinois residents add 5% sales tax. All sales CASH or 
COD. Allow three weeks for delivery. 



Send check or money order to: 



COMPARE OUR DEAL 



WE WILL NOT BE 
UNDERSOLD 




DuPAGE FM 
P.O. Box 1 
Lombard, ILL 60148 



Phone: 312-627-3540 




148 



73 MAGAZINE 



WAHE "iso-Tip" 

Cordless Soldering Iron 

Replaceable tips — Use ordinary solder — No cord to 
interfere — Ready to use instantly — Ideal to use on 
printed circuit boards, normal home and industry wiring 
repairs — Easily rechargeable — Place in separate recharg- 
ing stand when not in use — Recharges from "dead" to 
"full charge" overnrght 

Low voltage with high wattage performance — "Iso-Tip" 
soldering tip construction eliminates electrical leakage, 
the need for grounding and the possibility of damage to 
highly sensitive electronic components — Reaches solder- 
ing temperature in 3-5 seconds — Specially designed for 
good feel and balance — Saves time — Push button opera- 
tion — Built-in work light and pilot light. 

Tip performance equivalent of up to 50 watts and up to 
60 joints per charge depending on size of work — Long- 
life nickel cadmium batteries — Lightweight to eliminate 
fatigue . . weighs less than 6 ounces and is less than 8 
inches long — Complete safety and total portability — 
Do those hard-to-reach jobs — Goes where the work is 
— No drop cords to string or need to search for a power 
source. 

An IDEAL TOOL for: 

Radio, TV and Antenna Servicemen Aircraft Servicemen Hobbyists 
Home Owners Engineering Laboratories Electrical Departments 

from 




$19.95 



NEW HAVEN AVIONICS 



SPECIALS ! ! 



Collins R-391 Digital Readout Rx 500 kHz to 32 MHz 

Collins R 389 Digital Readout Rx 15 kHz to 15 MHz 

Hewlett Packard HP616 Microwave Sig. Gen. 

Boonton 202, 202C or 202E AM & FM 50 - 200 

Boonton 207 

Boonton 203 

Motorola OA 442 250 W Out on 2 MTR 

WANTED Top prices paid for: 



$500.00 
$500.00 
$250.00 
S250.00 
$800.00 
$800.00 
$375.00 






HP 628A 
HP8731B 



BOONTON 
235 A 



232A& 



all types of Collins test equipment 



Tweed New Haven Airport 

New Haven, Conn. 06512 

Phone: 203-467-0148 



JANUARY 1973 



149 



VRE PRICES OiN ELECTRONICS COMPONENTS RE ALL! GOING IP? Of mtt'M-i m> i know IY*r -iirrj.m w< <>rr uftlti; 

■ i|itriMnt llhil Hm'\ im\ Th< irir»inii in Ihr rlr( Inmti - ininpf uinit- InfriittV* i- ImU out: *jijt\* .111 i| ,r nvtt rn <if«l. * fill mil uliirr 
^iihlrfH-ihh n( ili-triliiihir'** jlulii\ t«j nrnrotiali* Uiu | ir i » p - !»■ > ,m-i ■ rl iii.jhiiI.ii Inri'iV int-ri-ijt.it il \ i- *jrr.ilK mlmi-il \l.nu itrni.v 
MJtrh a* TTL dr \\vf». LKW*. hiiiI MO** I.Sl .ir*- r.iliiinril. Our .uihir* ■"; VMtin*nlrr iimh li»r j muni ^to» kpilr n1 i i»iii|iiiitriif^ 

uhjlc ibi* hultlnis*lV |wn»lt!H j -fill rwt*. 



WAVEFORM GENERATOR, BF-5 
Just one of tCxe-s* BF-5 devices pro 
duces ikWj ujuaie. triangle, ram panel 
sawtooth vvavetntms without addi 
! ■ anal active oompon«nu. By adding 
a second BF-5, you can crealu Ampli- 
tude, frequ+'nev or ph$M modulate 
vaiiottes of these waveforms They 
ate able to replace large discrete waveform generators 
casting from S2QO.O0 to SI 300 00. Al the same time, 
they greatly reduce system weight and power con- 
sumption Full technical daia, P.C. layout, assembly, 
ariri hook-un instructions included. 
BF-S WAVEFORM GENERATOR*^™™, S&75 

GENERAL ELECTRIC PA -234, 1.4 WATT 

[POWER AMPLIFIER.,. S1.25 

This amplifier is housed in 3 plastic dual 
in I in e package with a tab for heat transfer. 
Has only tour active terminals, and requires only one 
capacitor for stabilization. Compatible with B, 16, or 
22-ohm loads. Applications include P. A. systems. 
phonos, movie projectors, TV, AM and FM receivers, 
GENERAL ELECTRIC PA-265, 5-WATT VOLTAGE 
REGULATOR. Housed m plastic dual in-line package 
with staggered leads end power tab. Usable over wide 
range of input and output voltages, input voltages 
to 37 volts and outputs from 3 to 30 volts; Usable in 
a wide variety of circuits. 

PA 234 POWER AMPLIFIER $1,25 

PA 256 VOLTAGE REGULATOR $1.25 

SUPER QUALITY I.C. SOCKETS 
Sockets made by T.I. and Cinch. All 
era low-profile, compact types. 
14 Pin Dip Solder Tale Sockets 

3 for SI 25 16 for 35 00 
16 Pin Dip Solder Tale Sockets 

2forSlH00 13 for $5.00 
14 Pm Dip Gold Wire Wrap Sockets 

2 for SI 25 IDforSS.OO 
16 Pm Dip Gold Wire Wrap Sockets 

2 for 51. 50 8 for 55.00 
10 Pin To 5 Gold Sockets (Cinch 1 

2 tor S1.00 13 tor S5.00 



s*L 



\v 



SINGLE CHIP 7-SEGMENT DISPLAY 
COUNTER, AND DECODER, That's right' 
A stngle chip TTL decade counter with 
latches, BCD outputs, a 7-segmem: decoder 
drivef r AND a 7-segmeni LEO displiv I with decimal} 
on fop. Only Q 15" thick (not Counting pi ns I , the chip 
mounts in i standard 16-pm DIP socket. Digits are 
0.270" high and can be latched in during the next 
count or blanked. 

\ SPECTRA - STRIP FLAT BONDED 

We know this is what everyone want! 
for then hame-brew projects, bfcSUSC 
they always ask for n. We now have 
over 5 by 10 G feet, but it won't last 
long, so order now before jfs all ^one. 
We don't want any broken hearts. Specs' 20 conduc 
tors. 24 AWG, 7 strands, size is SB" x .044". We could 
give all its virtues, but most people know them or could 
easily look it up m any industrial electronics house 
catalogue. 

Sh. Wi. 1 lb. 10 feei....0r<fct No. SSFBRC \H.l 
Price: S.35 lit Sl.00/3ft. 5500 18 ft 

$30.00/ 100 ft. $55.00/200 ft S10O.O0/40Q It. 
S200.00 900 ft S500.00 2000 



70WATT RMS AUDtO AMPLIFIER 
ft BASIC PACKAGE. STEREO S5.50 
Take advantage of $*gne tic's IME&40 
power drrver, tdass AB amp*. Oe- 
signed far 35 watts RMS pel Chan- 
nel Distortion .5% Iruquency response, ± .Brlb 
20Hz to 100H/ NE540 requires two power tran- 
sistors, a 2N5296 INPNI and a 2N6109 tPNP*. 
supplied pei NE 540, Kit package includes (21 
NE540, 121 2N5298, \2\ 2N6109, Information on 
P.C. tjoard layout, parts and circuitry, and a list of 
miscellaneous small parts required to build ilv> 70 
watt amplifier lor stereo. 
DNE540 

NPN 
PNP 



l.Ol.ll WI) OIMK \IKiN \l WW M i'Pl.fKS 



Q2N5296 35 watt 
D2M6109 40 watt 
D 70 watt Stuieo Kit 
n 35 watt Mono Kit 

HARDTOGET DIGITAL I.C/i 



S2 25 ea. 

75/ea. 
£5.&0/ea. 
S2.95/ea. 

SALE 



D 7447 BCD To-7 Segment Decoder Driver $1 .05 



07490 Decimal Counter 

D 7485 Comparator „ 

□ 74T92 UpOown Counter... 



... | t, m * ■ 



□ RCA CD40&T 



RCA CD4007 



Quad 2- Input Nor Gate 

I Cosmos) .-.—.. 

Complementary Pair St 
Inverter,,. ,... 

Hex Buffer. 



Hlllflll 



$ .76 

$1.25 
$1.45 

$1 .25 

ST. SO 
$1.50 



/ 



DRCA CD40tO 

MISCELLANEOUS SEMICONDUCTORS, SALE 

D MUS 4988 Silicon Uni lateral Switch. Useful 
for voltage-sensitive switch, sweep generators, 
etc. SI. 00 

D MUS A65 PNP High-Current Darlington Tran- 
slator. Super high gain in a small package 2/$1 
D MPS Al 4 NPN. SAME AS ABOVE 2 Si 00 

COMPACT BRIDGE 

2 Amp 200 Volt $ .60 

2 Amp 400 Volt Si. 00 

2 Amp &Q0 Volt St 50 

2 Amp BOO Volt S2.Q0 

2 Amp 1000 Volt $2 50 

4 Amp 400 Volt $1,50 

4 Amp 600 Volt S2.00 

4 Amp E00 Volt $2 50 

PLASTIC FIBER OPTICS. Plas 
tic optical monofibers are conve- 
niently card-mounted and avail- 
able in five different fiber diame- 
ters. Excelfent supplement for B 
and F Fiber Optic Kits to pro- 
vide additional fiber optic mater 
iai. Fibers available in diameters of 005" 1250 ft. 
cardK Offer design versatility to RSrD and product 
engineers. Specif i cations — maximum cont. oper. 
temp, 170 degrees Fahrenheit, acceptance angle - 
67 degrees, numerical aperture 0.55. transmission 
range 0.4 to 1 5 microns. YOUR CHOICE - Si .00 
iTIMER. to 2.75 MINUTES GENERAL 
mME. New packaged timers, for 1T5V, 
60 Hz. Ti mer cs set for 2.75 m Inutes ( 1 65 
secondsl of operation At the end of op- 
erating cycle, a SPOT switch is close 
May be reworked to provide any irme delay be- 
tween and 2,75 minutes. Makes a useful lab or 
sequence timer, Latest design with current list 
price of SI 5 00 

Sh.Wt 1 lb, TGT S2 75 ea. 

2TGT SS.DG-2 

SCSTAA62I UDIO AMPLIFIER 

I.C fludio pitiplififii jn t4 pin D\P packurje, prnvid-K 
up to 4 warn rxjwer hyith uropi-p Nwt sink, and 2B Volt 
iuppiv Can bl used if t2 VotBi with r-riiuced oiiliiui 
omwrjr Si 9& otopStOOO 



- Frgurir A, fjoneO 'ogtc wppry. ^ Volts at 1 Ampere, 
than circuit proof, uHtb r»>gh Jt^ut w uilri low f pipit 

$1600 

Figuri* A. pom-d Op Amp supply, +15 Volts, *nd t5 
Voln ai 5 Amperes. Mlg by Analog Devices, ^miliar 
to thuir modet D02 Short Circull proof, ultra high per- 
rof manct . S29 00 

Figure B, 5 Volt 1 Amp vgpo'v. ruguiitert bv F»if child 
93Cr5. ifiori orcuil protected Jg J^ 

Sam* « abovr, it\ kit form %J 75 

Mating connt tlor for vhoue $1 Q0 

Q 5 Voh 5 Amp regulated supply, by Bluiyna, (not 
shown I £23.00 

R^ CALCULATOR CHIP SPEClALIII 
One of the largest manufacturers of 
MOS Integrated Cii cults has discon- 
unued his three-chip iai m favor of 
a singk chip. This is the hobbyist's 
gam, since he can now obtain this fully tested, high- 
ly flexible sat at a fraction of what even the largest 
calculator manufacturers pay. Consists of three 24- 
ptn LC/s, has de bounced input, eight-digit capacity* 
1 decoded seven segment output, Full data included, 
8-Digit Floating-Point Calculator Set S975 

JH^[ FAIRCHILD VOLTAGE REGULATORS 
This is the UA 7300 Series. Three termi- 
nal regulator, with thermal overload pro- 
tection and internal current limiting, mak- 
ing it essentially blow-out proof. Because 
simple circuitry is used with this device, designing, 
regulated power supplies is duck soup. Output is rated 
at to 1 ampere; maximum input voltage 11 35 volts, 
Choice of voltages: 5,6.8,12,15,18, or 24 Volts. Order 
31 7805, 7806, 7808, etc. 

Voltage Regulator ^Specify Voltage)..™ $2.00 

4| SHRINK TUBING. B and F has a truckload 

=» of shrink tubing, but we still expect it to go 

fast. If you have ever used shrink, you know 

^JF it is i ndispftnsable for eta ctroni c construct! on . 

Made a wire too short? Just solice and shrink tubing 

over it and it will look like new. Pins too close? Same 

solution, Excellent results with hot-air gun r soldering 

iron, or even 5 match. This is polyolef in type where 

outer wail shrinks, inner wall melts to encapsulate wire. 

SHRINK TUBING ASSORTMENT, 25 fwt each, of 

1/8,3/16, 1 /4-inch tubing $5,00 

SPECTAL I.C-S, PHASE LOCKED LOOPS 

NE5A0 Pkaie Locked Loop ............. $4.65 

\F.561 Ptra- Locked Loop . . $4.65 

\ £562 Phase Locked Loop - 14.65 

NEorV/i Phi^r Locked l.4H)p •*:•*■.* »'i .•• i *.*.* $4.65 
NK."rSfiF inaction Geflerator/Tot>r Encoder, . $-L65 

NE,"it»7 I'LL/Ton* Decoder * $4,65 

\K5 C >5 Four Qiindriuil Multiplier. »*■.* * * » * .* (3.7,1 
NF.-.r-ri limrr. 2u Ser to I hour. Special . . . $1.25 
|| Send $.25 tot latest Catalog. 

UirilM- ttM.Kf *F.*Gtft NOrl >PHlrTElJ 
P05TACI V\UH\ THE I. S \. 

hiutt* * 1 h>r E ". in 1 r. 1 7 , ;,.j j -377* or liilt) r» ,12- 2323 

^ |LR4ik-\ntrr»aiit - M j ill- rrlnqjf, IMI.i>H mJUllmlii ^jf^ 

{J Q III II « plrw 



rndSJe* charge 1 



IE1IUID 



> 



B. A F. ENTERPRISES 

PMm ,ft*7l 5BJH3 
9 ltd* 44 n*.Kqjiw "imji^liMIIi 01*37 



BRAND NEW CATALOG THOUSANDS OF SURPLUS 



GIANT 2*/s" NUMERAL "NJXIE" CLOCK 
KIT 

I 



New I For fartcm**^ nfflre?.. jnd rornmrrru] est;ibli4i" 
tnrnbi. and Iboc people who like Urjr displays* rkar- 
jrlers appear is a bright continuous lint* ** hirh ran foe 
read from u > i«taiirri> as great as ISO fret. All dri*e 
rirt-uitN urr jolid ntale. and unit employs new DUftom 
LSI dock rhip. Indientee hour, minulr*. arid ^rmid, 1 ** 
\tav be *ir*-d hir :Il hour or 12 hour operation with 
a simpk jumper rhariPt*. Kit offered rnrtiplrte m itli i»r 
wittuiul rase for eu*tom inclination*. Paris Uirlude 
P.C. b«wii.*r>rkel». w*!id *lalr roinp)nrnK hardware, 
resistors raps, viewing filter, etc. 
*h.ttt. 15 lb^ 

With Ca« (;!\m;/i iw.r.o 

Without Ctfe CNNC $84J50 

LOW-PRICED M)IGH CLOCK KIT 



**Mi 



3 30 #s 



New. low-priced digital dork h ilh General Fleetrk 
7-scgmeiit n timer ir display lubes, in a styled w droit 
wood cabinet. In 1972. lV WXK nixie display clock 
made hifllurv b\ being the firKl and only rlock with 
electronic hours, minutes, and Mfcondi display under 
Si 00. Mkm Me- ha if broken the 550 pnee harrier for 
1973, and we douhl thai anyone in tnr n*-ar ititure 
will be able to matrh I hi-- *ufw-r-1nw price! Tht.% rerj- 
noim i« made po*>iJjJi* by a nm Lani*--*ralr in teg rat ion 
rhip, runh i m-d reigned fot a *i\-digil rloi k . (.Wk has 
BCD oillpul for rxternal dVvires. May he wired for 
21 or 12 hour operation wilh only a situ pie jumper 
rhangr, (.ompletc with all parts, sockets, tn>truHion 
manual, and real wcwid rase. Only a soldet in* iron and 
a screw driter are enquired. 

<h»t. I ft* I .Pill.* $-17.50 

SANKEIN HIGH POWER, HIGH PERFORM 
ANCKKIYKRH) \OU UiF. Kh(;i>LATC)KS 

These hybrid regolntiH-j* are rnjcy to 
um-, requiring no external compon- 
ent** Excellent for ope rational 
amplifier *upplirK logic *tipplies 
and other high performanrr app- 
lira lions. \H regulators have \ryi 
than 50 millivolts ripple and better 
than 1% line and load regulation, 
some mode I h l:u exceed big thin 



; 



&&A 



apecific.il ion. 

SI3I2UE 1 2* oils, I Ampere ... 

S13150E 13 toll*. I Ampere „. 

S132IOF 24 Wits, I Ampere ... 

: £13050 K 5 \ oils, I Ampere . . 

J SI3551M 5 Voll*. 3 -\mprna ... 

WIRE-WRAP COMPUTER WIRE 



.$2.25 



,. .$7.00 



New burpkis from a large computer companv Solid 
sirver -plated OFHC copper conduct o* Special riigii- 
lemperature, thin wall iniulanon of teflon, and other 
quality materials. Extremely rugged and flexible wire- 
wrap wire. In addition to usual applications, can be 
used for affective breadboarding, and wherever quick 
stripping of solid wire is desired. Different colors are 
now available. State first, secondhand third choice of 
colors, Shipping weight per 500* is 1 lb. 
Conductor Order No. 500" 1000' 10.000' 
Size 

30 WWW30(Ft.) S5,00 S9.00 S7S.00 

26 WWW26ifU S6.0G $11.00 S9S.00 

. 24 WWW24(fO S6.S0 S12-00 SI 00.00 



ROTARY THUMBWHEEL SWITCH 

Brand new digital switch, available with 
output in straight decimal form, or 
BCD. Widely used to set up predeter- 
mined counts or intervals, d>gi til values 

or digital to analog values. Prices quoted are per 

section, or decade. 

DECIMAL OUTPUT (10 position) RTSDCO $2,35 

SfNARY-CODED DECIMAL RTSBCD $2.35 

OUTPUT 

HIGH-TEMP. POWER TRANSISTOR 
2N1015D NPN Silicon 200W 

Power Amplifier 200V 10A S2.00 
1 for SI 7,50 or 1 00 for SI 50-00 

SANKEN HYBRID AUDIO 

AMPLIFIER MODULES, We 
.SI-1025A.1 I _^ 

1 have made a fortunate purchase 

of Sanken Audio Amplifier Hy- 
brid Modules. With these you can 
tiuild ymif own audio amplifiers at less than the 
price of discrete components. Just add a powei 
supply, and a chassis to act as a heat sink. Brand 
new units, in original boxes. guaranteed by Band F. 
Sanken,and the Sank en U,S. distftbuior. Available 
in three sizes: 10 watts RMS (20 watts music power I 
25 watts RMS 150 watts M.P.I, and 50 watts RMS. 
1 100 wait$ M.P.I per channel. Twenty -page manu 
factLjrer's instruction book included. Sanken amp 
lifiers have proved so simple and reliable ihat they 
are being used for industrial applications, such a* 
servo amplifiers St wide band laboratory application; 

DSU010Y 10 watt RMS amplifier. 

industrial grac^e .,„ S4,75 

DSH025A 25 watt RMS amplifier, 

industrial grade ._•- S14.75 

DSIIDSOA 50 watt RMS amplifier. 

industr ral grade S22,50 

DSI1025E 25wati RMS amplifier, 

economy grade..,. , ST 4.00 

DSH050E 50 watt RMS amplifier. 

economy grade.,, £21.00 

DTransfoimer for stereo 10 watt amplifiers 

|2 ihs.),. S3.95 

D Transformer for stereo 25 or SO watt 

amplifiers (5 lbs I S5.95 

H Set of 13) 2000 mfii 50V capacitors 

for 10-watt sterao, S4.00 

D Set of (3J 2200 mfd 75V capacitoj s 

for 25 or 50 watt amplifiers S5.00 
D4 Amp Bndge Rectrfier. suitable for ail 

amplif *urs..„ S? 00 

O Complete kit for 100 watt RMS stereo 

amplifier (200 watt musicl including 

two 50-watt Sanken hybrids, all parts. 

Instructions, and nice 1/16 + " thick, black 

anodized and punched chassis SS8.00 

DSame for 50 watt RMS stereo amplifier, 

includes two 25 watt Sankens, etc $58 00 

□ Same for 20 watt RMS stereo, includes 

two 10 watt Sankens. etc £30.00 

ELECTRONIC PRESET COUNTER 

This counter Is from a copying ma- 

- jfr-** chine. It uses two Durant electro- 

^ -. mechanical decade counters, and in- 

_v^ _ 

.^_^*Jyo^s a nice power supply, etc Two 

Vctary switches allow the unit to be 
3d preset with any number from 1 to 
50. When thn number of pulsos in reaches this couni, 
a rfllay opens, shutting off the controlled unit. Should 
be useful for cod winders, and other applications, re- 
quiring shut -off at a ptedeter mined count. The parts 
alone at our low price represent a "steal "\ as the unit 
has high quality switches, silicon rectifiers, transform- 
er!, etc, 
D Preset Electronic Counter { 6 lbs. } S6 75 



BARGAINS 

NOW OUT 



^fe 



DGU KITS 



D£CAD£ COUNTING UNITS WITH RE ADO UTS 

AhvAyi on* fl* B * F"i rptq.fl papuljr dimi. now «»n«) (o iridiid* 
..1m ikd bortrrtv I.C. luchvti, and nyht irigk mckfi Inr rpjdiiui Ai 
r Milled vi Ihflt un»T» £**\ h* Hi»ck«r nd<i by »d«' *n^ il'aiflh* pmch 
or Milt buftvd ihmugh fnr |M*uti ^onrwl and riHI SeworjiaiMrr 
rnl umri Mlt «*nl3blt «■ loHt>*i 



Ittqutfncy onunlan 
Uvd*i 



7490 Orvc HJ MHi tountir U-d 

HMfl 

74196 S#*m K Tl90«Pt«frt|Jrr*#!Ht4rSQMMj'wMT 

hifhM vmnrd na at tntvtubrihrv «i rvmd 
74133 a. Owtetionil Cawttrr. 33 MH; apt#«iio*i M»* tmo mpuX 
liftn one Thill rtrjk*i xh* vml eounr up. ttw oftrcf d***" 
U«i in dud* firTHr&.wfvirrp 1h« cQtmi«-r h pftHi to a »^mtit" 
4nd count* duwn (u »fo, mum lor i rug ■ iqquBrrcE nfumli, 
i * . k^epinq Irjcjb dI ponpl* m .■ room tiv EVUnlmg .m for 
mil ir» «nri rtui*n I r»r dt&ttiUitrt 
T47S AfMi !*ich uuttxluy Llwd hi OMintfi to dupUyicoiiXinu* 
0Vlpt*yx>f ItHIMrncv Pfhd* t»m luMjuwnr* il fjrinfl UkuCIIMl 
t*t ymnlTMuprrd dnflbf 
/ Ai7 Hjhl drtt*t»p n na iHilf P«i«i ba»c wrw*n Mf me w l 4«ipi«ii 
t^'cti n mctud+d lor *i« modbhl 

IMEWEST DCU! 

QCU criititMnfli #M wt !h^ lajivrof of our oIPmp count tug uniti. 
thil ii. high ipe«T couiinny, up-dciwii operjlion, MonflP. una p»*»t 
l'4 jddiltnri 4i indud*** efimfjafalttr llftBGiand « tlnj m trwh* r>l iwitch 
in onH-n to prow^i cflrn|uriion irtd prpwT ctp^Pililv Wiih rhu com 
bm*H43« V»m CAR do trw lr>Hoi*rnjj 
II Caunl Ltp o« down *t %p««di 10 33 M*taH*rtj 

i*»f* pfHKw cevni dumi raw count. 
3i Pr«*«r m tftf iuhwi count down ro* up* «nd ffncratB « lo«ie 

\*mmt «ta*i count ot M*tf m ntAchtd Stack M*na units ind om 

*rjt# logfc ir««l to* trnr courrr wrirttrf ftlan n'o 
4r fraii | To nrrj, court p up r .°* downl «nd ^enaiitt i logic ki*F lor 

tnv rtumpar Qrvatrr m vqud im ihr numbut ruvwl in lh« Thumti 

whi'Hl rwucti Sutk irvatjl DCU* «id general* i logic lenet tho* 

irvg whirfht-' nuenbti ii vfi^tvr thjm.nquiL la, ni Ifti Than numbeFi 

pr#i*1 on iwilcriirt 

M90 ?**7 CoutiMf O J5 

T«M M7S T44l7Count«r t» JS 

7*19b f*7S r447Cownlw SIC JB 

74142 7U7 Covnrti f9 7*, 

7419J f47S 7447 74» Uftvwta OCU 114 SO 

FUNCTJOIV CI AERATOR KIT 

IMPOSSIBLE! A 1700.00 function c^neralor lor 
SWJMI' Kut trur* Thr new. lovt rokttWK Jn") 
mtmnliihic Havetorm geflrntur inak<<- thi- prir<- 
po^ahlr. (lur kit uses two genera I or ckcuit- - ow 
fc a carrier genera I or. and produce? rifie* triangle, 
Mjuare, «j^t<K)th. ramp ajul puLne waveform^, Th# 
lecond t> j muilulalion generator, for implilude or 
lrfi|Ui'iU"ir iih mjmI.i I ion til" the output WttvtfOTSla- 
Oulpul rrequriiry raii£r i;* in»ni 20 Mi to 1-5 nirca- 
Ni-rljf. Modulation i< -^itrh-^lee table for inltrnal 
\M, hi I '-trial FM. nr extrrnal modulation, 
%k>del A R 620k Function Generator „ 199.00 






& 



cr 



Amp 
.5 Amp 



€POXY RECTIFIERS 

ACQ Volts 8 FOR St. 00 

1000 Volts 4 FOR Sr, 00 



n 



UJ 



Send S.25 for latest super catalog. 

All rmifi tHERE iWlSHT ^OT sr^t JF1EI* 

pi^T MLI PAID 1% THE! S V 
hk*r*du<intamiTi iii s:n « itii?isi3.iizs 

tfai*ViM.n^ -Mi*mI M1I 110.00 i 
CO.n *§ mUttm 



PsW»«*g 



,,,*%#!»• r * 



B.&F. ENTERPRISES 

Phone 167 7 J 533-2323 
P Bo* 44, H.iihurjiq. Massachy«t1i 01937 









—~ 



CALCULATOR ON A CHIP 
40 pin DIP package — 

Add, subtract, multiply, and divide 
12 digit display and calculate 
Chain calculations 
True credit balance sign output 
Automatic overflow indication 
Fixed decimal point at 0, 2, 3, or 4 
Leading zero suppression 
Complete data supplied with chip 




Only 89.95 



CD 3 Universal Counter Module 
Can be programmed to count to any 
modulus 2-9 for one kit, 2—99 for 
two kits, etc. Includes board, 7490, 
7447, RCA DR2010 Numitron display 
tube and five programming components. 
Full instructions included - perfect for 
displaying second, minutes and hours, etc. 

Complete $9.25 



LINEAR SPECIAL 

Ten (10) operational amplifiers with a two-page 
sheet of application notes covering the basic cir* 

cuits using op-amps . . ........ g .55 each 

Op -amp package 10 741% data sheet and applica 
tfon notes; 14 DIP, 8 DIP choice. .only $5 00 




LINEAR ICs (duaUn-Hne) 

LM I (10 positive voltage rcg. 

747 dual 74 I op arnp^DIP 

LM3G2 voltage follower op-amp 

70M operational amplifier 

711) voltage comparator 

LM309K 5 V-l A power supply module . . 
LM 380 2 watt audio amplifier 



- • .80 

* 1,00 

*- 1*25 

. , 35 
. . -50 
. .250 

, . 1.50 



DIGITAL COUNTER MODULE 30MC 
unit includes board, SN7490, 
SN7475 quad latch, SN7447 
7-segment driver and RCA 
"numitron" display tube 
W/decimaL 1" x 4.5" module *i* 
will mount on V centers. 

kit Sin 95 




wired and icstcd SI3 



C a T .,* . 



DIGITAL SPECIAL 
Ten brand new (on carriers) dual-in line JK flip- 
flops-LU321 with data sheet and two pages of 
application notes describing hookups for— divide 
by three through ten, and twelve Also self 
correcting ring counter hookups, etc. 

10 LU321 W/data $4.00 

TTL dual-in-line 

7400,7401,7402,7404,7405.7410, 
7420.7430,7440, 

7450,7451,7453 .. 100 for $18.00 

744 1 BCD decoder driver 

7442 BCD decoder , , 

7473 dual JK flip-flop 

7474 dual type D FF 

7475 quad latch . - . . 

7476 dual JK FF V.V*\\ 

7480 gated full adder 

7483 4 bit full adder . . . 

7486 quad exclusive or gale 

7489 64 bit RAM 

7490 decade counter \ , . "] 

7492 divide by 1 2 counter *...,. 

7493 4 bit binary counter . ...„ 
74 1 54 one of 1 6 decoder . . 

74192 up/down decade counter . , 

74193 up/down binary counter . , 

74]95unv.4bitSR 

8220 parity gen/checker 

8200 4 bit magnitude comparator, 

8280 preset decade counter . , 

8281 preset binary counter . . 
8520 25 MC divide by "N" 

mAAi 2t « 15 2.00 

7495 4 bit SHUT REGISTER . , . [J5 

8590 8 bit shift register . 2 00 

8270 4 bit shift register \\ \ \ 2M 



■ w • • 



* • * t 



20 
1.00 

.90 

.55 

.40 

1.15 

.55 

.50 

1.15 
.65 

3.00 
.90 

.90 
.90 

* 4 . * <t . 3 \J 

2.25 

. . * . 2.00 

J .00 

• • * . 1 .60 

• . . . i , i 3 

I I S 



" » 



LAST MINUTE ADDITIONS 

NE565 Phase lock loop, TO-5 

NE566 Function Generator, DIP (8 pin) . . . 
NE567 Tone decoder, DIP (8 pin) .,.,_., 

7447 7 segment decoder driver . . 

74181 Arithmetic Logic Unit, 24 pin, DIP . 

8261 fast carry for above 

8223 256 bit bipolar field programmable, 

read-only memory . . 

8570 9 bit SI, PO, shift register 

LED Red Emitting Lamp . . ..,...*.,*... 



$3.50 da, 
$3.50 ea. 
S3. 50 ea, 
. . . $1.30 

• , . S2.00 

<$7,5Q 

> . $2.50 

. . . S-60 



AM IC's are new and f ully tested — leads are plated 
with gold or solder. Orders for $5 or more will be 
shipped prepaid. Add 35rf handling and postage for 
smaller orders, California residents add sales tax. IC 
orders are shipped within two workdays of receipt 
of order — kits are shipped within ten days of 
receipt of order. Money back guarantee on all 
goods sold. 




BRBMLOn 





SEND FOR FREE FL YER 

P.O. Box J 
CARMICHAEL, CA 95608 

(916) 966-2111 



152 



73 MAGAZINE 



r 







Teletype Model 15 less 
cover with Synch Motor 
& Keyboard , . . . $49.50 

Model 19 with Synch Motor Keyboard (with 
built »n Tape Punch) and Trans, Drst. less tables 

£85 00 

Typing Reperf Strip Printer type $24.50 

Non typing 519.95 

Teletype Paper Carbon Type case of 12 roils 

Reperf. Tape 11/16 case of 40 rolls $4.95 

88 MH Coils Package of 5 $1.50 

Collins Variable Crystal 
Oscillator contains 18 
crystals mounted on a 
turret with a precision 
geared switching arrange- 
ment that selects the pro- 
per crystal and coil 
comb, thus giving a wide 
selection of freq. Crystals 
included (omitting frao 

tions) are 26 MC 27, 28, 30, 30.111, 31, 31.1, 
31.6, 32, 33, 34, 35,353, 36, 36.6, 37, 38, 
38,8 all mounted mside Crystal Oven only $9*95 



Wall Telephone with dial 
ready to mount and use 



Telephone Dial . $1 .95 

Field Telephone Wire 2 conductor 1250 foot 
reel $12.95 

Magneto Telephones con- 
sisting of a wood case 
with hand crank magneto 
and a cradle 

Wall Telephone 

and a cradle phone in like 
new cond $9.95 






Western Union Facsimile 

Unit Trans. & Rec. with 

60 Vy supply, 12 x 12 x 

6" used in many offices, 

complete with conversion "" '*. ^ 

sheets for . . , $9.95 Buy Six and get One FREE 

• Same unit but may need a little work.$4.95 ea. 

Paper for above, 100 Trans. & 100 Rec. sheets 

$1.95 for the 200 sheets 



OS-8E/S Oscilloscope. 
This is the "E A modef of 

this series which is a later 
version, portable 3" 
scope. Size 6 x 8 x 14" 
AC supply, 2 MC wide 
with carrying case Wt 12 
lbs ..«,_.... .539.50 









FR38 Counter same as 
HP524B, 8 places, Freq. 
Range 10 KC to 10 MC 
and can be used to 100 
MC to 200 MC and up to 
500 MC with proper 
plug-in (unit can be used 
to 10 MC without 
plug-in. Good cond. 

m m * * . Jj/sJ-UU 

10 to 100 MC plug-in . , - 

TS1060 Teletype Distor- 
tion Test Set. Compact 
3" Scope Indicator 110V 
60 Cy Power 6x 8 x 14" 

$14.95 

5 Level Punch Tape 
Reader. Range from 
0-250 WPM depending 
on pulse rate to solenoid 
$7.50 

Crystal Kit for PRC6 Waikie Talkie contains 42 
crystal in a metal carrying case $9.95 

TA1 Sound Power Unft 

Compact hand held. Just 
hook up wire and use. 
With built in generator 
for ringing. No Batteries 
Needed .... $12.50ea. 

GRC & PRC Equip. 
RT66 FM Transceiver 20 

to 28 £2750 

RT67 FM Transceiver 27 
to 39 MC >■.".« . .-,, $39.50 
RT68 FM Transdeiver 38 

to 54 MC $49.50 

R109 FM Receiver 27 to 

39 MC . $27.50 

Special PRC9 Back Pack 
Type WalkieTalkie 27 to 
39 MC in Exc. cond, with 
back pack access, and 
battery case ideal for 
general comm., hunting 
etc, ...,.,.... $49,50 

LR Frequency Standard 
Range 160 KC to 15 MC 
± .003% (to 60 MC ex- 
tended) with a 100 KC 
crystal. Wt. about 150 
lbs. Unchecked only 

APQ41 Radar X Band 
Transceiver with a 4 J 50 
Magnetron and a 2K25 
Klystron with all tubes 
compact Exc. Cond.* . . . 

Command Rec— Trans. 

3 to 4 MC 

190 to 550 KC . 

190 to 550 KC later version 




\ iff ■ — ' 



. $9.95 
. S9.95 
S12.50 








a. 3. mm® ws@m®m 

1624 South Main Street, Los Angeles CA 90015 

TERMS: Remittance in full or 25% deposit on COO order. Minimum order $5.00 FOB L.A. 



JANUARY 1973 



153 



New Years Counter Kit Sale: 






— t l 



NEW YEARS COUNTER KIT SALE: 

Here*s bnu it works; 

Place an order for over S 25.00 worth of merchandise 
at our regular low prices- Thcn»for each dollar worth 
of merchandise over S25-OO i you may buy one of rhe 
following kits: 

1, One each of 7490,7475, & 7447 for $1.50 

2, One each of 74192, 7475, & 7447 for S2,25 

OFFER EXPIRES FEBRUARY I0 f 1973- To take advantage 
of this sate, please mention the name of this magazine in vour outer. 



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iJul ytm flri- m,,i I,,,, n, t . jnl-fs 1211,00 wrll wurf y.m .. m ^ ITO-fMfQ COMPLETE TTL IC 

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d'fl -li»..i| rfrnnul pouif l|l« in a MP wkrt. f^j^tfd lifr lUi-r HHI Via. Kf|^laH> |14''"' m 
otipli Lola Threr *Tc lilt H\H NEW with full .lata J,r T | and 4-piaj Ml II ll't K\4M1 AupOVaill.lk 

NiMr. N«mJi n 7H7 Urn ilrim-T .n«l ONI: CtillHVM LIMITING UKSlS-fuH 1'EFl SEOMKIST, fti 
■ mi uppl] situ wrlfa ,.iir or Inn IhiMimnd KftOM S'illCK. Al» »allottlr H ±1 OVERFLOW dun ui 

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ORDER DESK 1 BOO 325 2595 (TOLt FREE) 

IWK Safirf StQte Sysfems, /nc. 

P.O. BOX 773 
COLUMBIA. MO 65201 




PHONE (314) 443-3673 
TWX 910-760-1453 



TOMS «MUinR>hMHi-l'^*. fHkrn Hwk w muwj <ifiln fitli oT4*f. |HNk \MI HP \KI» 

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ihHUtttlirf. 

viss'H it i REsitmrczs: rirjH-tdd r*^k>u%. 




NOISE ACTUATED SWITCH $1.35 
Solid state noise actuated switch fully wired, 

includes mike pick-up, amplifier, SCR switch. 
Actuates by noise or whistle. Useful for burglar 
alarms, lamp lighter, etc, 15 ft range. 



TS 323 FREQ. METER 
Similar to the familiar BC 221 except this one 
covers range of 20—450 mc, Accuracy .005% 
Used, guaranteed OK, less batteries, with 
schematic, TS-323 ship wt.35 lbs $50,00 



LIGHT EMITTING DIODES 3/S1. 00 
Ruby red, gold plated leads. With mercury ceJI 
for instant testing. 



Alpha-numeric keyboards. Excellent to new in condition. Styles may vary slightly 
from picture. Two models available, one with ASCI I encoder in base $55.00 postpaid 
in the U.S. Keyboard with no encoder in base $35.00 postpaid in U.S. 



KEY BOARDS 
$35.00 & $55.00 









IC BONANZA 



Brand new DTL dual inline (DIP) package, 
factory marked ceramic type. The price is 
too good to be true. Fully guaranteed and 
with specs. 




ALPHANUMERIC keyboard removed from 
unused IBM Selectric machines, Bargain 
price at only $8.00 



930 Dual 4 input NAND gate similar to 7420 

931 Clocked flip flop 

932 Dual 4 input Expand Buff 

933 Dual 4 input expander 
936 Hex Inverter 

945 JK Flip Fiop 

946 Quad 2 input gate 
962 Triple 3 input gate 



r * 



j * 



t§ 



If 



" 



ft 



if 



74110 
7440 
7460 
7405 

74110 
7400 
7410 



15* each. Buy $100 worth and deduct 10%. 

24 hour delivery guaranteed. 









GIANT B-7971 NIXIES (2) with 2 sockets 
and driver board containing hi voltage tran- 
sistors. Complete plug-in board as removed 
from operational equipment. Schematics in* 
eluded. Unbelievable but true,. . . just $2,50 
for the complete package. . . #72S-10 S2.50 



Please add postage for above, 
JANUARY 1973 



JOHN MESHNA JR. PO Box 62, E. LYNN MASS. 01904 



155 








NEW and SURPLUS ELECTRONICS FOR THE HAM 

and EXPERIMENTER 



T^TimeTlJaotuje. Electronic Clock Kit 



Step In£o7h« Future With 
TH: ffi MACHINE 

Small Size; 

2 1/4X4 1/2 X fi 3/4 



BASIC CLOCK 
ELECTRONICS (KIT) 

HAND-FifflSHED SOLID 
WALNUT CASE 

ALARM 
SNOOZE 
MANUAL RESET 
AUTOPOWEFt RESET 
COttDS DISPLAY 



$52$° 



10 



00 




J5 
2.00 

I. DO 



Introducing the most stylish, compact. fltate-oi^tht-art electronic clock kit available anywhere 

THE TIME MACHINE utilizes the latest electronic taduUques and advances to provides time 
information Ukg no cloak has before . A Large Scoln Integration (L6() circuit providon trie tegic 
to cv fiver the 5CI hertz line frequency into a di&playable time. Internal options include a 
presflUable alarm circuit, five minute snooze . and 24 hoar time. 



METER MARKER GENERATOR 

KIT 



19 




WAHL 



PROVIDES A M.\RKER SIGNAL ON ALL STANDARD 
2 -METER FM CHANNELS. INCLUDING THE REPEATER 
JNPirr AND OtfPUT CK ^S WELL AS D01ECT 

\WNEI . 



Greatest advance 
in soldering since 
electricity. . . 



COMPLETELY PORTABLE 

HEATS tH S SECONDS 

SOLDERS UP TO ISO JOINTS 
OR MORE PER CHARGE 

RECHARGES AUTOMATIC ALL V 
IN ITS OWN STAND 

HO AC LEAKAGE OR INDUCED 
CURRENT TO DAMAGE DELICATE 

ELiCTRome components 



$ l9 95 

NEW- GUARANTEED 



COMPtETE WITH RECHARGING STAND, HUE TH» AND 
INSTRUCTION BOOKLET 



I 






l^i^ 






1 ^ 




I 









TOUCH CALLING 
KEYSET 

A 12-hutton( alptut-nuBflrlc 
koyout equipped with a 
ton* ftaritrratar; identical 
to these i»«j in ?oaeh 
Cillic: t*l#pfcon«, ?h« 
ton* c*s*rator Lc wanted 
on a, print** circuit card 

Sack $r tfc* Ittyati* 
AM ten frvqwQt)Cl*d mx-m 
jr&iuc*i by a ane— 

SBistar oscillator. 



SIZE: 
3.55" X G.21T X 2.12 



24 

NEW 



95 



5VDC 

3/4 AMP 

POWER 
SUPPLY 
KIT 



USES THE LATEST STATE-OF-THE-ART THREE TERMINAL REGULATOR 
CIRCUITRY, 

HAS INTERNAL CURRENT LIMIT, THERMAL SHUTDOWN , AND 
SAFE -AREA COMPENSATION. 





*4.400 k- 



"7 Segment LED 
Display 

3*§ EACH NEW! 

u 

J_ SFMIUAK TO MANSANTO MAN- 1 AND 

OPCOA STA-7. PITS IN I A FlU DIP SOCKET . 



DISPLAY KIT i, INCLUDES! 7 SEGMENT LED, 744" . $ 5 95 

AMD 7490. 

DISPLAY KIT 2. INCLUDES*. 7 SEGMENT LED, 7447, 7490, 6,95 

AND 7475. 




"47-3Z3^ 



KA ELECTRONIC SALES 

1312 SLOCUM STSCET « DALLAS, TfXAS 7520? 



WHEN IN DALLAS VISIT OUR STORE 
SATURDAY 9 TO 5. 

SEND YOUR NAME IN FOR MAILING 
LIST AND CATALOG. 



COMING SOON: TOUCH-TONE DECODER KIT. 




J 



Save over $9,000.00 on this 



AN/WRR-2SSB Receiver! 

Original government cost: over 
$10,000.00! One of Navy's most modern 
radio receiving sets. Built by National 
Radio Co. in last decade. A triple con- 
version super-heterodyne. Frequency 
range: 2 to 32 MC. in 1 kc increments. 4 
bands. Featuring full carrier suppression, 
unit receives AM, CW, MCW, voice, facsim- 
ile, Teletype and ISB. REQUIRES NO 
MODIFICATION! Greatly superior to 
earlier R390A/URR model. Good cond. 
Complete, operational. Spec sheet avail- 
able. Spare parts as needed. Overhauled and certified . . . $595.00 





NAVY TCS TRANSMITTER 

Just arrived! This collector^ item is now 
available in new condition! 1.5 to 12 Mc. 
CW and AM. 50 watt CW. Ideal for a raft 
of multi-purpose uses. Designed by 
Collins Radio. Brand new! A Columbni 
special ,*•..,**.•..*•••.»«••. $75.00 



COLUMBIA SLASHES TEST 

TEST EQUIPMENT PRICES! 

• TEK., H.P., G.R. ETC. 

World's largest storehouse of meters, signal gen- 
erators, scopes, etc. All popular models. Immedi- 
ate delivery! 

Write for lowest prices in country! 



IP-69/ALA-2 PANADAPTER 

This compact unft can be used with most Ham 
Receivers after conversion. Complete with con- 
version info and schematic. Good condition 



!'*'•* 



■ . m i 



$19.95 



2 METER AIRCRAFT MONITOR 
RECEIVER 130-150MC 

R-748/TRC-47 single channel AM crystal con- 
trolled 110V 60CPS, pwr supply & speaker built 
in, squelch,, r f gain, dual conversion modern 
design. Size 19"W x 5"H x 14"D for rack mtg. 
Supplied with schematic & hookup info. No 
conversion required. Exl condition ..... $29.95 

XMTRS - TRANSCEIVERS - RECRs 

T 47/ART-V3 2-1 SMC transmitter Less tubes — 

Good condition ..,••, * $14.95 

T -47/ ART 13 with tubes Exl. Condition . . . 49.95 
RT-18/ARC-1 transceiver l00-156Mc ExL Condi- 

tion 39.95 

ARC-3 transmitter 24 channel 100— 156Mc Exl. 

Condition , , 14,95 

BC-34S 200 500KC & 1,5 18MC Reconditioned 

24V DC 75,00 



R^444/APR-4Y AM & FM Excellent Condition 

49 QB 

R105/ARR-15 1.5 — 18MC Collins Receiver, 

Good . $49.95 

RBB 600-4000KC Recond. 1 15/1/60 .... 100.00 

RBC 4-27MC Reconditioned 115/1/60 . . . 100.00 

ARC-3 Receiver 100— 156MC 24 Channel Exl. 

Condition 14.95 



URGENTLY WEEDED! 

We will pay top dollar for your late model 
military communication equipment, and mMi- 

tary/commercial lab grade test equipment. Write 
or call today; 

(213)875-2970 



{213)764-9030 



FM TRANSMITTERS & RECEIVERS 

70-100 Mc. Single channel. 50 W. output. 
110 V, 60 cycle. New and like new. 

FM9/TRC-1 Receiver , , . . . . S75.00 

T-14/TRC-1 Transmitter ..,.,,. 75.00 

FREE schematics. Convertable to 

6 or 2 meters. 



TELETYPE EQUIPMENT 

M-15KSR Page Printer 
w/ Keyboard & Table 
M-28KSR Page Printer 
M-28ASR Teletypewriter 



Tested OK 

$ 199.50 
795.00 
1750.00 



CV89A/URA8A RTTY Audio Type Terminal 
Unit r Good condition, less cabinet 75.00 



COMMAND Receivers Transmitters 
RECEIVERS 

190-550KC Q 5er Good Condition ,.. 

Or Like New 

6-9MC 40 Meters Good Condition 

XMTRS 

2.1 3MC T 1S/ARC-5 New 

45.3MC T 20/ARC-5 Ext. Condition 

4-5.3MC BC 475 New 

MD 7/ARC-5 Plate Modulator For Above 
ExL Condition - k - 



$14.95 
. 19.95 
. 12.95 

. . 4.95 
. . 3,95 
, . 5,95 
Xmtrs 
. . 4.95 



I 



Columbia Electronic Sales, Inc. 

P.O. Box 9266, 7360 Atoll Ave., North Hollywood CA 91609 Tel (213) 875-2970 & 764-9030 



WAT "FLANGELESS" 



Volt* 
4,7 

TOP MAT ZENERS " 5 for * | 
Type TK, Metal Catal $1 gj 



Volt* 

10, 

11. 

12. 

13. 



vort* 

15. 

30- 
33, 



*ki 



Tim* 



^ PC Board Incliid^ 1 
~ WORTH *30.00 

• -harass ■agsw^ * CSSS 

board wixn ■* , 



2 11 TRANSISTOR 

PHILCOAM RADIO CHASSIS 

V *- BUY 2 FOR Um mi I^TK^T* 

STEREO % Mlh* .mpliftar I**-* iV 
Pfiofio ampliffarj 
Tap* amplifier I 
Cov#n 355 Kc* to 
15 00 Kca Broa dealt band 
AC or DC 

Originally design for portable p+iono 
systems, and tape cassettes! 

One of the most versatile AM Radio and multi-purpose 
amplifiers we have seen at Poly Paka famous "Economy" 
price. Measures only 4Va" x 3" x 2" high. With tuning 
capacitor, IF circuitry* loopstick, ant., volume control 
witli switch. AC and phono-mike jacks. Separate h witch 
for chan^inf? from AM radio to amplifier* Uses either 
1I0V plug-in adapter (not with unit) and a !>-volt 
battery power. Exceptional sensitivity and power. Peed* 
into 16 ohm speaker* Complete with spec sheets, dia- 
gram** and hookup ideas. • With Built-in Preamp 

• Mike, Tape* Phono Inputs 



BRAND NEW LOWEST PRICES 



GENERAL 
ELECTRIC 



P 



3 FOR $6*00 



$fc 



!c3 



-livers 3. 



•WATT AUDIO AM 



heat 



watta cijptinuoua. 10 watts 
sinks; micro-mini size: 3 4 *i ot* *" o 

tereo phonos, tape. FM. AM. TV. *ervo. 



ife. 
to 3it\ 
mono 



U ith 

SUp- 

and 



12-DIGIT "CALCULATOR ON A CHIP" 

Similar to Mo±?tek sflOl. Outperforms Texaii B- 
diRtt TMS1HQ2. A -10-pin DIP, Adda* multiplies, 
subtracts, and divides. Use with 7-#t'gtTient 
readouts, Nixies, ami LED's. We include sche- 
matic** instructions from factory' to build cal- 
culator, 3 for $35 



Only 



$12.95 





COUNTING 

SYSTEM 



Includes SN7 490. der- 
ide counter, SN7475 
latch, SN744 1 BCD de- 

roder driver. 0-to-9 
Nixie tube, instructions. 



$4.50 

3 tor 

si a. oo 



Lowest prices cm 



4.50 




8 TRANSISTOR 
AMPLIFIER 

CHASSIS 



LED READOUTS a "„ » 

0-9 plus letters, 
for SNT44 6 or SNT4 4 7 
SiiapH in 1 4 -pin DIP 
socket. :i .tJi 3 hS ;i n", 
characters; V^W'. 
5 V, 2 1) -mil* per seff, 
charade rn : ! /4 * li / I S " 
FamouA MAN-1 type, 
D Sockets + S0 ea. 






$2.95 

Bui 3 

Tah* 10% 

Thi* display is excellent fur 
small portulik* ulectronica, 
such as DVM's, calculators, 
etc. Equivalent tn Monsanto 
MAN :iA, Operates from &V . 
2ft milliamperes. with 4 7 
uhro droppinjc resistor. 



Only 

$3.95 



GIANT 
SALE ON 

NATIONAL 

"IC'S 



Same a* above, except no AM radio lection. 
Completely wiredl With built-in preamp, 
mike, phono and tape Inputs, Dolor- Coded 
wires with diagram ami hookups. Works olf 
9VI><" transistor battery, Excellent fidelity. 



IT 



Bur 100 
T«h» ap% 



f* 



*S^ MAGIC d 

-SOUND TRIGGER" 



$1.98 



Lniciue Scientific Device, '"hand claps", sensitizer vr 
tai mike amplifier, trifffcers SCR. Needs only 3 to 6vdc. 
Use aa burglar alarm, intrusion device. Use with photo 
cell, triggers SCrVa. relays, LEB*s + Even fiber opti<- Uffhl 
pipe may be used, With hand booklet. 




LOWEST PRICES ON "TRIACS' 



* Two SCRs in one cist: • Mo&t complete listing ! 



PRV 

B0 

100 

200 
100 
400 
500 

600 



8 imp 

□ $.33 

.52 

B-72 
.59 
1.15 

Q 1.39 
Q 1.69 



10 amp 



a 
□ 



.64 

] 1.10 
D 1.39 



15 amp 

D$.es 

) 1.25 
i 1.45 
! 1.85 
I 2.55 



25 Amp 

i 5.85 

D 1-OS 

I 1.45 

! 1-65 

D 1.95 

] 2.25 



SILICON TUBES 



] 5U4 
i SR4 

866 



51.49 
3.95 
7.95 



— — a _ 

Codr J 4* 6 jmp TO 

JO iimp TO ©6. J 5 & 15 jmp uud 



Type 

™ DM8091 

] DM8093 

Q DM8054 

D DM8200 

1 DM8210 

] DM3220 

} DM8223 

□ DM8250 
G DMB281 
G DM8288 
a DM8502 
["I DM8520 
Q DMS555 
D DM8680 

□ DMB8O0 
D DM8830 

1 DM8845 
DM8845 
DM 86 80 



. , ■ - 



Description 
Tri-State Quad Buffer 
Tri -State Quad Buffer 
Tri-Siati- Quad Buffer 
4 -Bit Comparator . . . 
v Channel Switdi 
Purity Generator Checker 
Pr€>Kr«mmable ROM ►•..•• 
Binary to Octal ht-^oder . . 
Prespl Binary Counter . . * - 
Preeel Divide by 12 ♦ . . . . 

Same a* 7-1 107 

Modulo Divide by 2*10 . . . 
lYi -Siate Preset Counter , . 
Binary Counter ......... 

Dual Vollatre Translater . . . 
Dual Diff. Une Driver . . . , 
Same as SN 7 44 5 ,,»,.,,, 
Same aa SN ■ 145 4....*.. 

Hi Amp, 7-Seg. Dec. Driver 



NATIONAL 4 for 
DTL "IC'S" $1. 



"How's Your 

MEMORIES 

For I973 TI 



H DM930 
Q DM930 
G DM932 
□ DM936 
] DM946 



4 in. Gate 

4 In, Gate 

Dual 14 In. Buffer 

Hex Inverter 

Quad 2 Input Gate 



□ DM962 Triple 3 In. Gate 

D DM9093 Dual J-K Flip Flop* 

•2 for $1.00 



NATIONAL $2,95 
REGISTERS 3 for se.oo 

Dual 25 Bit 

Dual 50 Bit 
Dual 32 Bit 
Dual 100 Bit 

Dual 100 Bit 
1024 Bit Accumul 
I MM5O10 500/512 Bit 
Q MM5017 Dual 500/512 Bit 



Q MM50O 
Q MM502 
Q MM505 
D MM506 
G MM5006 
D MM5013 



Q 1101 256 Bit RAM MOS 

D 1103 1024 Bit RAM MOS 

D 2S13 Character Gen. ROM 

D2516 Character Gen. ROM . 

D74S9 64 Bit RAM TTL 

I f 8223 Programmable ROM . 

Q 6224 Programmable ROM . 
G MM5260 1024 Bit RAM . ., 

] 4000 Sit Core Memory Plane 



viiii 



$3.50 

8.50 

12.50 

12.50 

3.50 

8.50 

12.50 

6.88 
4.95 




PLASTIC RTL'S 
ByFarrchil 

Choose Any 

2 for $1.00 

D 900 Buffer 

U 914 Quad 2 Input Gate 

G 923 J-K Flip Flop 





$3.33 



12VDC 
POWER PACI 

I tO VAC to 
12 VDC@ 
1.6 amp 



Terms: add poRtage, rod's 25 ^ - Rated; net SO 
Phone iirdtr^: Wakefield. M.»«. C61T1 245— 1> 
Retail: i *; - 1 ^ l>^l Carmine St.. W.ikt?tield. Mafia. 
<..il Water Sm-rt i C.OJI/S MAT HK PHtlNKh 



\H 



'<* 



15C catalog on Fiber Optics. *ICs\ Semrs. Parts 

POLY PAKS 

P.O.BOX B42A, LVNNFIELOMASS 01140 



HIGH POWER EPOXY RECTIFIERS 



□ 2000* 
3000 
4000 



SALE 5000 2.25 

1 00 □ 6000 2.96 

135 S000 3.50 

1.65 G 10000 3.95 



1AMP 




EPOXY SILICON 

RECTIFIERS •micramini 



P1V 
50 
100 
20O 
4 0O 
€00 
800 

XOOrt 



EPOXY 

rectifie! 

specialV 

10 for $1 

a i amp 

to 00 PIV 



t» 



LINEAR 



FACTOAV CUAJtAJVTriD 



op Amps 






«F J 



'I 

531 
532 
533 
536 
537 
540 
550 
555 

556 

558 

560 

561 

5 62 

565 

566 

567 

595 

702C 

703C 

709C 

7 IOC 

71 1C 

723C 

741C 

741CV 

747C 

74SC 

709-70* 

709CG 

739-739 

75450 

42S0 



• 1 o% a 



'^OUFI| 



Hi slew rate op-amp , . .! 

Micro power 741 TO-S .,._,,, 

Micro power 709 * * . . , , 

FET input op amp . . . . . « . . , . . 
Precision 741 TO~5 ^ ,.,,««*. , 

7pW pwr driver amp 

Precision 723 voltage reg, . . . . 

Tinier 2 uSeconds to 1-hour 

5 Times fatter than 74 1C , , . . 

Dual 741 (mini DIP) ....... 

Phase lock loops 

Phase lock loop DIP . ..*.._., 

Phase lock loop DIP. ......... 

Phase loch loops <Aj , 

Function generator < Mini DIP J , . . 

Tone decoder \ Mini DIP} , 

Four quandrant multiplier + . . . . 

Hi-galn ( DC amp, TO-S , , . 
RF-IF, amp, 14 ckt*. TO-5 
Operational amp {Af . . . , 

Differential amp (A) ........ 

DuaT diff. comp (A) 
Voltage regulator iAi 
Frequency compensator 709(A) 
Frequency comp 709 (mini DIP) 

Dual 741C, (A | , 

Freq. adj. 741C (A) , 

Dual 709C (DIP) 

Gold, military, DIP .,,.».«. 

Dual stereo preamp *..,*,, 

Relay line driver ...,....., 

Programmable op amp 



SN7400 

□ 5N7401 .21 

5N7402 .21 

5N7403 .21 

SN7404 .27 

1 SN7405 ,27 

SN7406 .45 

SN7407 ,45 

5N7408 .29 

5N7409 .29 

SN7410 ,21 

D SN7411 .25 

SN7413 .75 

SM7416 .48 

SN7417 .48 

SN742 .21 

SN7421 ,21 

SN7426 .32 

Srf7430 .21 

SN7432 .25 

SN7437 .50 

3 SN7438 .51 

D SN744Q .21 

SN7441 l.oo 

D 5N7442 1.12 

5N7443 1.21 

D SN7444 1.21 

5N7445 1,50 

8 5N7446 1.17 

SN7447 t.25 

3 SN744S 1.25 

• Factory Marked! 
Factory Guaranteed! 



LOWEST PRICES ON 

TTLICV 

Buy 3 — Take 10 W* Discount 






•**nt 



I 



Q SN74SO 
1 I SN7451 
Z\ SN745 3 
3 5N7454 
U Shf7455 
SN7460 
5H7470 
5N7472 
SN7473 
5N7474 
SN747 5 
SN7476 
D SN7480 
SN74S1 
3 5N7482 
D 5N74Q3 
3 SN7486 
D SN7489 
Q SN7490 
SW7491 
SN7492 
5N7493 
SN7494 
5N7495 
SN7496 
D SN74100 
SN74107 
5N74121 
□ SN74122 



I 



D SN74123 
3 5N74141 

□ SN74145 
SN741SO 

Q SK74151 

SW74153 

D SN74154 

a SN74155 

□ SN74156 
SN74157 

D SN74158 

D SN74160 

SN74161 

3 SN74162 

3 SN74163 

D SN74165 

D SN74174 

SN74175 

□ SN74180 

SN74181 

SN74182 

^ SN74184 

SN74185 

CI 5N74192 

SN74193 

SN74194 

SN74195 

D SN74198 

D SN74199 



$2.50 
TUBE SALE 



ry 



Burroughs 87 97 1. O-to-D, A-to^ 
Z, 2 1 '_►" high characters. 17UV. 



ALLEN BRADLEY'S 
MICRO-POTS' 

T*jn> 0, I 2" dtjt. v 
1 y high, Mounts 1 r- 
hi»li*, with -iiift, 1 1 iv. 

immerihiipr) -|iriiui litgli 

2 for SI 

Ohms U 2.5 
[D 75 G S.C 

r ioo 7 

SOO lO 



|(G) Military Gold Pnk 

A) TO-H, tn DIP duol in line pak 

Potter & Brumfield 

KAP RELAYS 



-■ 



t* -* 



Your choice 
3 for $7, SO 



$2.98 



u 



115 VAC 3PDT 
12 VDC 3POT 



92.98 

2.98 



G 25.K 

Z 7 5-H 
; 100. K 



We mock Lockout Bushing & 
Screwdriver types i at sume 

low prices. 



INTEGRATED^ 

CIRCUIT 
SOCKETS 

Buy Any 3 T*h* 10*. 

O 14-Pin. duel in line 
16-Pin, dual in lin* 
G T0-5< 8 or 10 pint 



S.45 

.50 
.29 



Excellent for "HAM" use &s antenna switching, lntching, 
tran-smii. receive, etc., and lOfTa of commercial or in- 
duHtriid uses. Inc-lmU>s plastic dust*cover with diagram 
and hookup info. 1 I -pin plug-in base. Contacts movable 
guld flashed silver, stationary overlay, with silver cad- 
mium oxide movables, All contacts 10 amp SPDT, Coil 
datdpUSVAC 2250 ohma, 17.6 ma, 12 VDC 21 miLs 
16S ohms. Sim: 2l' 4 * * 1 5/16*. Wt. 4 oes. Center pin 
missing, Comar Mfg. type equal too. 



$1.95 



a 

Only 

For measuring fiounaor noise 
levels. Essentially low 
range rectifier tvpe volt, 
meter. Internal imp. 3900 
ohms. Steady state refer- 
ence 1 mw. For 600V hne* 



paneC 

METERS 




$1.98 



PHILCO-FORD 
DYNAMIC MIKE 

Replacement for tape re- 
corders, FA systems, audio 
amps. 200 ohms. 6-ft. cord 
and mini mike plug. 200- 
5000 Hs. Wt. 6 o£. Fits in 
"palm of hand/* 2 3 /s" x 
is fl rf i "*/■''* Impact plastic 



ALLEN BRADLEY'S 
'TRANSISTOR' POTS 

Type F. Se re wu river adjust. 



Ohms u 100K 

75 Q 250 D 1*0K G 7.5K G 25.K [ ] 250K 
J 10O Q 500 G 2,5K D !0,OK G 50. H [ ] 2 Meg 
Q 200 D T50 G 5.OK □ 20,0K H 75, K | 1 5 Mefc 



Any 4 
for $1 



Poly Psks Will Never 
Be Undersold! 

I'HAM' UHF 400 MC 
HIGH POWER 
TRANSISTORS, 



Tin- lowest price riigilu-1 dork kit (with rublnelf as 
far as we citn st?e in U.S. A, Scientific devices* engi- 
nci-nag dept. io**l* extra patience in designing to give 
you the finest digital clock kit Using the latest tech* 
nnjufH in an e as y- to- understand booklet. The rabjnet- 
mciking section gives it the "interior decoruiing" touch 
so that it may fit into any room at home, shop or 
office. Walnut laminated tapered front cabinet, with 
gn Id -line front. Tapered legs for easy viewing. Large 
QJB. 7-segment fluorescent "blue-green" polaroid 
glow for the latest easy-viewing. FEATURES: *» display] 
tubes, completely rtrhed and thru plated circuit board. 
all iC's. Includes BCD outputs for use with timer 
options, may be wired for 12 or 24 hour display. 
Indicates HOURS. MINUTES, SECONDS. 115 VAC 60 
cy, Cllft packed. Wt. 3 lbs. * a" g 51^" g 3" Case 



DIGITAl 

CLOCK KIT 



By Scientific 
Devices 



Only 



WITH CASE 
Buy 3 — Take 1 % off 
Smaller & pgore 
compact 



Only 



$3.95 




2.50 



3 lor 510. 



By RCA or equal 2N3 632. 
NPN, 2:* watts, :l amps, 
TO- 60 CttftCj with stud mtg. 
VCEV max fi5. 




ALPHA-NUMERIC 7 SEG READOUTS 

Hiiiirt^tvnT ll|ue-tiret*n 0-9 numanlt, decimals and |*tt#rs. 

II. v 1A . <"h»ir.irti*r?; Kiljifrifnt V 
Lf HflKl-7* 1.75 m 1.7* .360 * .S70'' 1.5 V AC /PC 42 mils - &«efc*t — 
SUM 7* 1.6 *O.J75" .40 * .20" 1.5V *C /DC 42 mill ^ Sock, l 

•Compatible to 7-Mgminl driver IC f *. 



-••^•4 



t t 



t_i 



itsftof 



mil 



MIMl-7 



SLIM 7 



Dollor 
Stretcher/ 



j a. J I rails 



?! 



_ 3 — "LCDS", visible, micro-mintalure, 

2 **LtOS", infrared, jumbo. Tu- I ^ . 

] 2 ■■LCDS", risible, jumbo, red, TO- 1 * . Si 

a 1 — '"LEO", m-L ihu-, parabolic reflector, RCA Si 

□ 1 PHOTO TRANSISTOR* with darlington ;ini|i Mti-r, Ipns, . . 51 

D2 PHOTO TRANSISTORS, wild rhirlmRlon ami>, 2N:"777, (JF.tl 

□ 4 — photo CELLS. t'luire* H pancake, 30K-7Q ohm« Si 

U S - — SOLAR CELLS, round, sn. reel., nuq pr»wertriri?uils Si 

2 — SILICON SENSORS. TEXAS, M -'iS MalHistik, %isibk 51 



4 WATT AUDIO AMPLIFIER 

Type ^N 7 6024. Good up In TO hi. 4 W. into an s*ohm 
load- Ihch input im|wdmnv. VOC &V to 24. I»IP pak 
with heat sink, 15 tninsLsturs. 5 diodes. 



3 for S9 



D 



$3.95 



NATIONAL u OP" AMPS 

JiP* Description 

3 Watt amplifier 
Svper 723 V. regulator TOS 
i-performance amp 



D 

O LM-300 

LM-301 
D LM-302 

1 LM-304 
I] LM-305 

LM-307 
D LM^308 
LM-309H 
LM-309K 
LM-3SO 
LM 370 
LM-373 



Buy any 3 

Take 10 % 

SI. 95 
1.49 



Voltage follower TD5 . , , 
Neg* voltage regulator TOS 
Pos. voltage regulator TOS 

Super 741 

Super gain op amp T05 . 
SV 200ma V. regulator TOS 
SV i amp V. regulator T03 . 
Dual peripheral driver TOS 
AGC sojuetch aop amp TOS , 
^m-Fm if strip TOS 



KIDDE "DORANICK" 
REED RELAYS 



Only 
$1.49 



Hermelirally sealed to 1 2 
VDC. SPOT. Good for 
1.000,000s of switching 
cycles, a 50 DC ohm*. 1*0 A 
25 0V contacts^ 15 wntts. 



2 a 4 



X 1 



** 



-l OS. 



EPOXY 

FULL WAVE 

SILICON 

BRIDGE 

RECTIFIERS 



PIV 

SO 
IOO 
200 
400 
600 
800 
100O 
Code: J 
6 Amp 



2 Amp 
□ S-69 
.79 

i 1.19 

) 1.3S 

i 1,59 

G 1-79 

amp T<J-fi 



i ■> 



= *> 



t> Amp 
G S.8S 
,99 
: 1.25 

I i.so 

r 1.75 
a 1.95 

□ 2.25 
- ;i*e 

\ / I ft sq | 



Terms: add poaLasre, cod's 3R*3k Reted! nei 'A 
Phone Orders: W;ikelii-ld, Muss, (C1T) 24r>-'AK2K) 
Retail: 16-18 Ilrl Carmine Sl + , Wnkefieid. Muss, 
toll Water Street I CUD 'S MAY BE PHONKD 

, O ISC CATA10S oft Fiber Onlics f - ICs\ Semi's. Parts 

POLY PAKS 

P.O. BOX 942A. LYNMFICLD.MASS. O1I40 



r 






READER SERVICE 

Please either tear out this list of advertisers and send it 
in to 73 with as many boxes checked off as you would 
like to see brochures, data sheets or catalogs . . . or 
else make a copy and send that in. Include your zip 
code, please. 

ADVERTISER INDEX January 1973 



D 


Adirondack 64 


a 


Am. Wholesale* 84, 
118, 127 


a 


ATV* 119 


o 


Babylon 152 


D 


B & F 150, 151 


n 

D 


Bomar 122 
Callbook 123 


D 

a 
a 


Circ. Spec. 87 
Clegg 9, 11 
Columbia 157 


a 

D 
D 

a 

a 


Cornell 199 
CushCraft 143 
Data Eng. 76 
D Si T Enterprises 

118 
Drake 52 


D 

a 
a 


Dupage* 148 
DXer Mag. 119 
Else. Dlst. 104 


D 

a 


EL Instruments 81 
Estes 114 


D 


Fair 118 


a 


J.J. Glass 153 


D 

a 


Gregory 105 
Hal" 118, 119 


D 


Hamshack 111 


a 


Harrison 96 


u 


Henry 6, 7, 46, 59 


a 

D 

a 


Hobby Industries 28 
Hy Gain 106, 107, 
108, 109 
Jan 98 


a 


Janel 1 14 


D 
D 


Jeff-tronics 1 14 
Jensen 127 


D 


J & R 70 



127 



D KA Sales 156 

□ KW Industries 
Cover il 

D Mann 145 

D Meshna 155 

D MFJ 98 

□ Military Elec. 

□ MorGain 70 

O New Haven Avionics 

149 

D NHE 132 

□ Novice Mag. 119 
O Pal omar 103 

O Payne* 95 

D Pearce Simpson 119 

D Poly Paks 158. 159 

Q Regency 122 

Q Robot 58 

□ Savoy Cover IV 
D S electronics 147 
D Sentry 13 

D Signal I 30 

□ Slep 146 

O Solid State 154 

O Spectronics Cover I II 

D Standard 1 

O Tel rex 88 

D Top Band 2 

□ Topeka FM 127 

□ Unidyne 143 
D Vanguard 103 

D VanW2DLT 143 

D VHF Eng. 43 

D Vibroplex 98 

D Walter 129 

□ Windjammer 125 
Q World QSL 119 



73 Stuff 

73 Subscriptions 56, 57 
Rig of the Month, 116, 117 



*Reader service inquiries not solicited. Correspond 
directly to company. 

Mail to Readers' Service 

73 INC., PETERBOROUGH NH 03458 
PLEASE PRINT OR TYPE 
Name _^ Call 



Address 



160 



PROPAGATION CHART 
J. H. Nelson 
Good (Open), Fair <□), Poor (0) 



January 



1973 



Sir* Mon Tmf ffid Tku Fn Sat 


J 2 3 4 5 6 




7 




O 


® © 


1 1 




12 




'3 






H 


15 l6 17 l8 I9 20 


21 11 23 24 


2 5 




26 




27 






28 




29 


30 31 















Possible aurora 9 and 1 



EASTERN UNITED STATES TO 



GMT: 


00 


02 


04 


m 


08 


18 


12 


14 


18 


18 


30 


33 


ALASKA 


7A 


7 


7 


3A 


3A 


M 


^ 


IA 


7 


7A 


1i "14 


ARGENTINA 


TA 


7 


7 


7 


7 


7 


14 


14 


MA 


14A 


2T 


IT 


AUSTRALIA 


U 


78 


78 


73 


7 


7 


7 


7 


14 


14 


14 


14A 


CANAL IQNl 


14 


T 


7 


7 


7 


7 


7 


14 


,'l 


21 


21 


21 


ENGLAND 


? 


M 


*A 


3 


3 


3A 


7A 


MA 


14ft 


%A 


7 


T 


HAWAII 


14 


;h 


y 


7 


/ 


f 


3A 


14 


TB 


14 


21 


21 


INDIA 


3A 


1 7 


7B 


3B 


IB 


38 


TA T* 


78 


78 


7 


7 


JAPAN 


14 


7* 


TB 


3A 


lA 


3A 


3 


7 


1 


38 


78 


7 


MEXICO 


H 


7 


T 


* 


1 


? 


7 


M 


31 


31 


31 t 4 


PHILIPPINES 


7 


7B 


TB 


38 


» 


38 


■A 


7 


7 


78 


38 


38 


PUERTO ft ICO 


7 


7 


7 


T 


7 


3 


7 


14 


14 


14A 


14A 


M 


SOUTH ft F RlCA 


1 


7 


! 


* 


78 


78 


14 


31 


31 


t4A 


14 


14 


US £ K 


3A 


IA 


3A 


: 


1 


3A 


78 


14 


14 


78 


78 


.IA 


WEST COAST 


14 


7 


7 


7 


7 


7 


3 


7 


14 


31 


31 


31 


CENTR 


AL 


ur 


sin 


"ED 




rEi 


S TOrl 


ST A" 


ALASKA 


14 


T 


7 


3^ 


3A 


3A 


IA 


3A 


} 


14 


14 


14 


ARGENTINA 


14 


7 


j 


1 


7 


7 


7 


14 


14A 


14A 


21 


31 


AUSTRALIA 


14A 


14 


7H 


7B 


9 


7 


7 


7 


14 


14 


14 


14* 


CANAL ZONE 


14 


r 


7 


7 


T 


7 


T 


14 


3T 


31 


31 


11 


ENGLAND 


7 


7 


7 


3 


1 


3A 


T 


14 


14 


14 


78 


7 


HAWAII 


14A 


14 


7 


7 


7 


7 


7 


U 


7 


14 


11 


31 


INDIA 


1A 


? 


7B 


38 


38 


38 


7 


7 


7 


78 


78 


rti 


JAPAN 


14 


TB 


7 


3A 


3A 


3A 


3 


3A 


1 


38 


TB 


14 


MEXICO 


14 


7 


7 


7 


7 


7 


3 


7 


14 


14 


14 


14 


PHILIPPINES 


14 


7B 


TB 


38 


3B 


LIB 


3ft 


3A 


7 


7 


38 


7 


PUERTO FllCO 


14 


7 


t 


7 


1 


3A 


T 


14 


21 


14A 


14 


1 * 






SOUTH AFRICA 


14 


7 


7 


7 


TB 


TB 


TB 


14 


71 


14A 


14 


14 


U.S. S R, 


E 


3A 


3A 


3 


] 


3 


3 


7A 


7A 


TB 


38 38 



WESTERN UNITED STATES TO: 


ALASKA 


14 


7 


7 


I 


3 


3 


3 


' 


3A 


7 


jlE 


ARGENTINA 


14A 


14 


7 


7 


7 


7 


T 


7* 


14 


14A 


21 


71 


AUSTRALIA 


31 


71 


14 


78 


7 


7 


7 


7 


3 


14 


14 


14 


CANAL ZONE 


14 


T 


7 


7 


7 


7 


7 


7A 


71 


71 


21 


31 


ENGLAND 


7 


7 


7 


3 


3 


3 


3 


7 


14 


14 


78 


TB 


HAWAII 


21 


MA 


14 


7 


7 


7 


7 


3A 


7 


14 


31 


31 


INDIA 




14 


78 


3S 


38 


38 


3A 


3A 


T 


7 


78 


78 


4APAN 


= 4A 


14 


1 

?Er 


3A 


3A 


3A 


3 


3A 


7 


38 


' 


14 


MIX ICO 


14 


7 


7 


7 


7 


7 


3A 


7 


14 


T4 


71 


14 


PHILIPPINES 


71 


141 

■J 


78 

1 


» 


38 


3 


3 


3 


7 


7 




14 


PUERTO RICO 


14 


7 


7 


7 


7 


7 


7 


M 


31 


31 


11 


I4A 


SOUTH AFRICA 


14 


3 


7 


7 


TB 


7B 


38 


78 


*4 


14A 


14A 


14 


U. S. S. fl. 


3A 


3A 


3ft 


3 


3 


38 


in 


7 


7 


7 


38 


38 


EAST COAST 


M 


7 


7 


7 


7 


7 


3 


7 


14 


21 


21 


11 



A = Next higher frequency may be useful also 
B = Difficult circuit this period. 



73 MAGAZINE 






Yaesu presents the great 
two-meter leap forward 



Since Yaesu makes and sells more factory-as- 
sembled amateur rigs than any other company 
in the world, it foflows that well only place de- 
pendable, fully-perfected products on the market. 
So now, after more than two thoughtful years 
of development, here are our entries in the two- 
meter FM field: 

YAESU FT-2 AUTO 




Great new features — like Auto-Scan and a spe- 
cial Priority-channel — place the FT-2 AUTO in 
a class by itself. These unique capabilities are 
achieved with advanced digital-logic circuits. 
Here's how they work: 

With Auto-Scan on, the receiver scans all 8 
channels at 20 channels per second, Indicator 
lights provide a visual channel display, stopping 
on receipt of a signal At the end of each trans- 
mission, the receiver continues to scan. {Just 
push a channel button to skip over any channels 
you wish eliminated from the scanning cycle.) 
To lock on any frequency being received, simply 
depress the mike button momentarily. The lock 
light then glows indicating that transmitter and 
receiver are working together. To unlock, you 
again hit the mike button and the receiver con- 
tinues to scan. 

Only Yaesu offers this type of remote, one- 
handed control of the scanning function. 

The Priority-channel feature allows automatic 
monitoring of a preselected frequency. When 
the receiver stops on a frequency other than the 
Priority-channel, Auto-Scan will check every two 
seconds to determine if the Priority-channel Is 
busy. If it is, the receiver reverts instantly to the 
Priority-channel. Manual or Auto-Scan mode of 
operation is Instantly selectable on front panel. 
In manual mode, the push buttons function as 
channel selectors. 

SPECTRONICS WEST 

1491 E 28th, Signal Hill, Ca. 90806 / (213) 426-2593 

SPECTRONICS EAST 

Box 1457, Stow, Ohio 44224 / (216) 923-4567 



The FT-2 AUTO will operate from either 117 
V AC or 12 V DC power sources. 

Receiver/transmitter specifications include 
selectable 10 Watt or 1 Watt power-output levels: 
a frequency-adjustable tone-burst generator for 
repeater activation: 0.3 uV sensitivity for 20 db 
quieting; 10,7 MHz crystal filter, in addition to a 
455 kHz ceramic filter, for superb adjacent 
channel rejection; adjustable deviation and mike 
gain controls; Hi~Q slot-coupled resonators used 
in receiver front end; all solid-state construction. 
with diode-protected MOSFET input stage. 

This exciting new rig is available now. Just 
send your check for $329.95 — or use Master 
Charge or BankAmericard. We'll even include a 
free anti-theft mounting bracket that locks up 
your rig when its going mobile. 

YAESU FT-2FB 

This new unit features the same receiver/trans- 
mitter specifications listed above for the FT-2 




AUTO 
(without 
the scan 
feature), 
but in a 
compacted 
x2 1 /z x 10- 
inch package 
that weighs only 
4 lbs. The FT-2FB 
has 12-channel cap- 
ability, with illuminated frequency readout. It 
operates directly from a 12 V DC source, This 
rugged, handsomely-styled transceiver is yours 
for only $229.95. (A matching AC power supply 
with rechargeable batteries for emergency oper- 
ation is available for $79.95.) 

Both units come with a one-year warranty and 
are backed by Spectronics* fast, dependable 
service system. Act today, and be glad you 
waited for the finest in two-meter FM. 



□ Send FT-2 AUTO. Enclosed find $329.95* 
D Send FT-2FB. Enclosed find $229.95/ 

□ Send more data. 



I 



Name 



Address. 
City. 



State. 



Zip 



•California residents add 5% sales tax. 

NOTE: Both units are supplied with crystals for simplex 
operation on 146.76 MHz, 146.82 MHz, and 146.94 MHz. 
Additional crystals are $5.00 ea. 



. * 



t 



u 





HIGH ACCURACY CRYSTALS 

FOR OVER 30 YEARS 




Postpaid in U.S.A. 




TYPE 900 A 



TYPE 901 



Either type for amateur VHF in Regency, Swan, Standard, Drake, Varitronics, 
Tempo, Yaesu, Galaxy, Trio, Sonar, Clegg, SBE, transmitter or receiver. GE, 
Motorola, RCA or Oven use $4.95. Quotes on others. 

Specify crystal type, frequency, make of equipment and whether transmit or 
receive when ordering. 



* 



A*wr» 






«M 







BASSETT VACUUM BALUN 




L 



BASSETT VACUUM TRAP ANTENNA SYSTEM 

Complete packaged multi-band antenna sys- 
tems employing the famous Bassett Sealed 
Resonators and Balun from which air has 
been removed and replaced with pure 



helium at one atmosphere. Operating bands 
are indicated by model designation. 



MODEL DGA-4075 
MODEL DGA-204075 
MODEL DGA-2040 . 
MODEL DGA- 152040 



$59.50 
$79.50 
$59.50 
$79.50 



The famous sealed helium filled Balun . . . 
employed with the DGA Series Antenna 
Systems. Solderless center insulator and 
easily handles more than full legal power 
while reducing unwanted coax radiation. 
Equipped with a special SO-239 type coax 
connector and available either 1:1 or 4:1. 

MODEL DGA-2000-B . . $12.95 
Postpaid in U.S.A. 



* ■ 






CONTACT YOUR DISTRIBUTOR OR WRITE FOR DATA 



Inc 



P.O. Box 7157 - Fort: Lauderdale, Florida - 33304 

Tel: 305-566-8416 or 305-S47-11S1